Correct login debug log message
Correct login debug log message

I noticed the following message in a daemon log:

```
attempting v2 login to registry endpoint {%!s(bool=false) https://registry:5000 v2 %!s(bool=false) %!s(bool=true) %!s(*tls.Config=&{<nil> <nil> [] map[] <nil> 0xc82075c030 []  0 <nil> false [49196 49200 49195 49199 49162 49161 49172 49171 53 47] true false [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0] <nil> 769 0 [] {{0 0} 0} {{0 0} 0 0 0 0} []})}
```

loginV2 tries to log an APIEndpoint as a string, but this struct does
not have a String method. Log the actual URL that will be used as the
endpoint, instead.

Signed-off-by: Aaron Lehmann <8ecfc6017a87905413dcd7d63696a2a4c351b604@docker.com>

mahak/docker,gigidwan/docker,containers/storage,q384566678/docker,mgoelzer/docker,estesp/docker,shubheksha/docker.github.io,diogomonica/docker,mstanleyjones/docker,msabansal/docker,shishir-a412ed/docker,mtrmac/docker,tklauser/docker,londoncalling/docker.github.io,imkin/moby,dnephin/docker,geekylucas/docker,tophj-ibm/docker,POLJM242/docker,yongtang/docker,dmcgowan/docker,kencochrane/docker,lixiaobing10051267/docker,jvanz/docker,alfred-landrum/docker,sanjeo/docker,haveatry/docker,BSWANG/denverdino.github.io,tianon/docker,rkazak/docker,johnstep/moby-moby,mike1729/docker,miminar/docker,LuisBosquez/docker.github.io,noxiouz/docker,johnstep/moby-moby,YuPengZTE/docker,kerneltime/docker,jecarey/docker,sarnautov/moby,sarnautov/moby,mathewkoshy493/docker,nalind/docker,HideoYamauchi/docker,tklauser/docker,moxiegirl/docker,shin-/docker.github.io,alexisbellido/docker.github.io,sunyuan3/docker,laijs/docker,tonistiigi/docker,jameszhan/docker,haveatry/docker,yummypeng/docker,umerazad/docker,nguyentm83/docker,portworx/docker,justyntemme/docker,bdwill/docker.github.io,BenHall/docker,pramodhkp/moby,shishir-a412ed/docker,shin-/docker.github.io,inatatsu/docker,erikstmartin/docker,14rcole/docker,ibuildthecloud/docker,achanda/docker,madhanrm/docker,afein/docker,Microsoft/docker,TrumanLing/docker,dims/docker,YuPengZTE/docker,14rcole/docker,dongjoon-hyun/docker,jhorwit2/docker,tagomoris/docker,asbjornenge/docker,bdwill/docker.github.io,srust/docker,Altiscale/docker,srust/docker,danix800/docker.github.io,sdurrheimer/docker,trebonian/docker,alexisbellido/docker.github.io,JimGalasyn/docker.github.io,akira-baruah/docker,paralin/docker,inatatsu/docker,jthelin/docker,dperny/docker,estesp/docker,mike1729/docker,jlebon/docker,dnephin/docker,thaJeztah/docker.github.io,allencloud/docker,jlhawn/docker,KingEmet/docker,stainboy/docker,darrenstahlmsft/docker,gnailuy/docker,troy0820/docker.github.io,denverdino/docker.github.io,Ramzec/docker,geekylucas/docker,Tenk42/docker,paralin/docker,nawawi/docker,mahak/docker,yosifkit/docker,joeuo/docker.github.io,brahmaroutu/docker,stevvooe/docker,Microsoft/docker,djs55/docker,joeuo/docker.github.io,mikebrow/docker,dperny/docker,AkihiroSuda/docker,docker/docker,POLJM242/docker,kunalkushwaha/docker,mtanlee/docker,JimGalasyn/docker.github.io,moby/moby,yummypeng/docker,runcom/docker,SvenDowideit/docker,gdevillele/docker.github.io,bluebreezecf/docker,nalind/docker,x1022as/docker,dsau/docker,dsau/docker,containers/storage,jecarey/docker,toli/docker,docker/docker.github.io,gnailuy/docker,twaugh/docker,BSWANG/denverdino.github.io,gschaetz/moby,haveatry/docker,hqhq/moby,maxamillion/docker,runcom/docker,AkihiroSuda/docker,vdemeester/docker,menglingwei/denverdino.github.io,anujbahuguna/docker,thaJeztah/docker.github.io,pramodhkp/moby,jwhonce/docker,BSWANG/denverdino.github.io,JimGalasyn/docker.github.io,dongjoon-hyun/docker,gnailuy/docker,BSWANG/denverdino.github.io,KingEmet/docker,justincormack/docker,alfred-landrum/docker,Morsicus/docker,akira-baruah/docker,LuisBosquez/docker.github.io,yp-engineering/docker,joaofnfernandes/docker.github.io,miminar/docker,shubheksha/docker.github.io,nawawi/docker,ajaymdesai/docker,jlhawn/docker,Tenk42/docker,jhorwit2/docker,trebonian/docker,PatrickLang/moby,bearstech/moby,thaJeztah/docker.github.io,HuKeping/docker,x1022as/docker,bonczj/moby-json-file-logger,shishir-a412ed/docker,mgoelzer/docker,denverdino/docker.github.io,rancher/docker,KarthikNayak/docker,tagomoris/docker,pradipd/moby,moul/docker,ndeloof/docker,wenchma/docker,scotttlin/docker,willmtemple/docker,bluebreezecf/docker,amatsus/docker,tophj-ibm/docker,gigidwan/docker,lixiaobing1/docker,splunk/docker,imkin/moby,abhinavdahiya/docker,isubuz/docker,paralin/docker,mikebrow/docker,harche/docker,rancher/docker,rkazak/docker,kerneltime/docker,mgoelzer/docker,errordeveloper/docker,OnePaaS/docker,moby/moby,nalind/docker,cloudflare/docker,madhanrm/docker,charleszheng44/moby,darrenstahlmsft/docker,moypray/docker,pyotr777/docker,Morsicus/docker,stevvooe/docker,Syntaxide/docker,jongiddy/docker,PatrickLang/moby,sanscontext/docker.github.io,denverdino/denverdino.github.io,joaofnfernandes/docker.github.io,ajaymdesai/docker,aduermael/docker.github.io,HideoYamauchi/docker,KarthikNayak/docker,denverdino/docker.github.io,alexisbellido/docker.github.io,whuwxl/docker,crosbymichael/docker,brahmaroutu/docker,jwhonce/docker,umerazad/docker,dims/docker,mtesselH/docker,13W/docker,docker-zh/docker.github.io,sfsmithcha/docker,jimjag/docker,charleszheng44/moby,duglin/docker,pecameron/docker,TheBigBear/docker,phiroict/docker,djs55/docker,DoraALin/docker,docker-zh/docker.github.io,justincormack/docker,michelvocks/docker,LuisBosquez/docker.github.io,docker-zh/docker.github.io,laijs/docker,noironetworks/docker,phiroict/docker,sheimi/docker,abhinavdahiya/docker,imkin/moby,docker/docker,crosbymichael/docker,coreos/docker,zhuguihua/docker,catinthesky/docker,catinthesky/docker,OnePaaS/docker,mtesselH/docker,toli/docker,TrumanLing/docker,pradipd/moby,noironetworks/docker,phiroict/docker,mahak/docker,projectatomic/docker,hypriot/docker,yosifkit/docker,rhatdan/docker,sdurrheimer/docker,endophage/docker,catinthesky/docker,shin-/docker.github.io,LuisBosquez/docker.github.io,mohmost12/docker,rillig/docker.github.io,icaoweiwei/docker,laijs/moby,rhatdan/storage,dccurtis/docker,rremer/moby,twaugh/docker,DoraALin/docker,YuPengZTE/docker,kencochrane/docker,Syntaxide/docker,Mokolea/docker,ibuildthecloud/docker,abhinavdahiya/docker,bluebreezecf/docker,Shopify/docker,noxiouz/docker,gschaetz/moby,KarthikNayak/docker,cyphar/docker,kencochrane/docker,tklauser/docker,moypray/docker,tmp6154/docker,joaofnfernandes/docker.github.io,jhorwit2/docker,sean-jc/docker,cyphar/docker,konstruktoid/docker-1,menglingwei/denverdino.github.io,moxiegirl/docker,endophage/docker,moul/docker,naveed-jamil-tenpearls/moby,yp-engineering/docker,johnstep/docker.github.io,londoncalling/docker.github.io,denverdino/denverdino.github.io,errordeveloper/docker,jzwlqx/denverdino.github.io,charleswhchan/docker,sanscontext/docker.github.io,denverdino/denverdino.github.io,JimGalasyn/docker.github.io,erikh/docker,Mokolea/docker,duglin/docker,charleszheng44/moby,justyntemme/docker,sanscontext/docker.github.io,BSWANG/denverdino.github.io,msabansal/docker,tonistiigi/docker,gschaetz/moby,thaJeztah/docker,shubheksha/docker.github.io,joeuo/docker.github.io,jimjag/docker,resin-io/docker,vdemeester/docker,darrenstahlmsft/moby,konstruktoid/docker-upstream,danix800/docker.github.io,jimjag/docker,yp-engineering/docker,naveed-jamil-tenpearls/moby,yasiramin10p/moby,kunalkushwaha/docker,mikedougherty/docker,fcrisciani/docker,denverdino/denverdino.github.io,dperny/docker,PatrickLang/moby,michael-holzheu/docker,ffoysal/docker,kerneltime/docker,djs55/docker,tianon/docker,aduermael/docker.github.io,troy0820/docker.github.io,denverdino/denverdino.github.io,yongtang/docker,JMesser81/docker,duglin/docker,jameszhan/docker,kolyshkin/moby,mkumatag/docker,jameszhan/docker,ajaymdesai/docker,alexisbellido/docker.github.io,LaynePeng/docker,OnePaaS/docker,bdwill/docker.github.io,jvanz/docker,willmtemple/docker,LuisBosquez/docker.github.io,mtrmac/docker,danyalKhaliq10p/moby,joaofnfernandes/docker.github.io,rancher/docker,hypriot/docker,jthelin/docker,cpuguy83/docker,raja-sami-10p/moby,unclejack/docker,ibuildthecloud/docker,anweiss/docker.github.io,splunk/docker,ibuildthecloud/docker,diogomonica/docker,liaoqingwei/docker,trebonian/docker,portworx/docker,portworx/docker,rillig/docker.github.io,kojiromike/docker,danix800/docker.github.io,ColinHebert/docker,harche/docker,anujbahuguna/docker,qudongfang/docker,konstruktoid/docker-1,liaoqingwei/docker,TrumanLing/docker,johnstep/docker.github.io,thaJeztah/docker.github.io,bfirsh/docker,unclejack/docker,dgageot/docker,TheBigBear/docker,sheimi/docker,tophj-ibm/moby,cyli/docker,icaoweiwei/docker,troy0820/docker.github.io,mstanleyjones/docker,13W/docker,xiekeyang/docker,anweiss/docker.github.io,erikh/docker,bonczj/moby-json-file-logger,sunyuan3/docker,sterchelen/docker,zhuguihua/docker,alexisbellido/docker.github.io,projectatomic/docker,thaJeztah/docker,thaJeztah/docker,jlebon/docker,docker/docker.github.io,jwhonce/docker,sfsmithcha/docker,darrenstahlmsft/docker,joeuo/docker.github.io,thaJeztah/docker,BenHall/docker,AkihiroSuda/docker,laijs/moby,pyotr777/docker,johnstep/docker.github.io,danix800/docker.github.io,mkumatag/docker,xuxinkun/docker,joeuo/docker.github.io,nghiant2710/docker,xuxinkun/docker,dsheets/moby,twaugh/docker,danyalKhaliq10p/moby,Microsoft/docker,coreos/docker,justyntemme/docker,dsheets/moby,umerazad/docker,konstruktoid/docker-upstream,prertik/docker,Altiscale/docker,johnstep/docker.github.io,errordeveloper/docker,dims/docker,coolljt0725/docker,ColinHebert/docker,gjaskiewicz/moby,allencloud/docker,noironetworks/docker,shhsu/docker,dsheets/moby,londoncalling/docker.github.io,ibuildthecloud/docker,KingEmet/docker,coreos/docker,mtrmac/docker,denverdino/docker.github.io,prertik/docker,HuKeping/docker,kunalkushwaha/docker,fcrisciani/docker,shin-/docker.github.io,ColinHebert/docker,kolyshkin/docker,moypray/docker,prertik/docker,Mokolea/docker,ndeloof/docker,JMesser81/docker,mstanleyjones/docker,bearstech/moby,mikedougherty/docker,estesp/docker,bfirsh/docker,Shopify/docker,Ramzec/docker,noxiouz/docker,lixiaobing10051267/docker,erikstmartin/docker,shubheksha/docker.github.io,mtanlee/docker,sunyuan3/docker,shubheksha/docker.github.io,amatsus/docker,eskaaren/docker,cr7pt0gr4ph7/docker,pecameron/docker,cyli/docker,michael-holzheu/docker,gnailuy/docker,mohmost12/docker,x1022as/docker,michelvocks/docker,gigidwan/docker,johnstep/moby-moby,13W/docker,denverdino/docker.github.io,cr7pt0gr4ph7/docker,mahak/docker,medallia/docker,kolyshkin/moby,yummypeng/docker,mtanlee/docker,achanda/docker,menglingwei/denverdino.github.io,qudongfang/docker,wenchma/docker,splunk/docker,ripcurld0/moby,tkopczynski/docker,flavio/docker,toli/docker,moxiegirl/docker,gdevillele/docker.github.io,raja-sami-10p/moby,docker/docker.github.io,vdemeester/docker,sfsmithcha/docker,joaofnfernandes/docker.github.io,projectatomic/docker,aduermael/docker.github.io,SvenDowideit/docker,nawawi/docker,menglingwei/denverdino.github.io,charleswhchan/docker,asbjornenge/docker,erikstmartin/docker,brahmaroutu/docker,jzwlqx/denverdino.github.io,stevvooe/docker,ffoysal/docker,Shopify/docker,erikh/docker,laijs/moby,medallia/docker,danyalKhaliq10p/moby,TheBigBear/docker,flavio/docker,ripcurld0/moby,paralin/docker,thtanaka/docker,miminar/docker,sterchelen/docker,AkihiroSuda/docker,cr7pt0gr4ph7/docker,konstruktoid/docker-upstream,mathewkoshy493/docker,bearstech/moby,pramodhkp/moby,whuwxl/docker,tophj-ibm/docker,pecameron/docker,tkopczynski/docker,xiekeyang/docker,thaJeztah/docker.github.io,charleswhchan/docker,coolljt0725/docker,coolljt0725/docker,eskaaren/docker,sanscontext/docker.github.io,rhatdan/storage,nghiant2710/docker,phiroict/docker,yongtang/docker,aduermael/docker.github.io,maxamillion/docker,sdurrheimer/docker,konstruktoid/docker-upstream,msabansal/docker,dsau/docker,tmp6154/docker,dgageot/docker,trebonian/docker,phiroict/docker,HideoYamauchi/docker,allencloud/docker,Mashimiao/docker,medallia/docker,jlebon/docker,dgageot/docker,jvanz/docker,zhuguihua/docker,docker/docker.github.io,ripcurld0/moby,jzwlqx/denverdino.github.io,hqhq/moby,scotttlin/docker,jongiddy/docker,stainboy/docker,pyotr777/docker,dnephin/docker,inatatsu/docker,sanjeo/docker,rhatdan/docker,thtanaka/docker,madhanrm/docker,xuxinkun/docker,liaoqingwei/docker,cloudflare/docker,yosifkit/docker,bdwill/docker.github.io,JMesser81/docker,nguyentm83/docker,LaynePeng/docker,Ramzec/docker,Ramzec/docker,alfred-landrum/docker,sheimi/docker,JimGalasyn/docker.github.io,medallia/docker,gjaskiewicz/moby,lixiaobing1/docker,gdevillele/docker.github.io,maxamillion/docker,kolyshkin/moby,afein/docker,shhsu/docker,nalind/docker,bfirsh/docker,docker/docker,cyli/docker,laijs/docker,justincormack/docker,sanscontext/docker.github.io,HuKeping/docker,dongjoon-hyun/docker,diogomonica/docker,moul/docker,jzwlqx/denverdino.github.io,geekylucas/docker,harche/docker,moby/moby,tagomoris/docker,londoncalling/docker.github.io,resin-io/docker,yosifkit/docker,srust/docker,achanda/docker,gdevillele/docker.github.io,rhardih/docker,cyphar/docker,isubuz/docker,anweiss/docker.github.io,YujiOshima/docker,konstruktoid/docker-1,jlhawn/docker,yasiramin10p/moby,troy0820/docker.github.io,hypriot/docker,BenHall/docker,qudongfang/docker,thtanaka/docker,londoncalling/docker.github.io,rremer/moby,Tenk42/docker,flavio/docker,raja-sami-10p/moby,xiaods/docker,xiaods/docker,cpuguy83/docker,willmtemple/docker,rhardih/docker,michelvocks/docker,michael-holzheu/docker,rillig/docker.github.io,lixiaobing10051267/docker,13W/docker,icaoweiwei/docker,kojiromike/docker,jongiddy/docker,johnstep/docker.github.io,tophj-ibm/moby,docker/docker.github.io,mixja/docker,hqhq/moby,YujiOshima/docker,pradipd/moby,cloudflare/docker,sean-jc/docker,jimjag/docker,mohmost12/docker,nawawi/docker,YujiOshima/docker,mixja/docker,bdwill/docker.github.io,darrenstahlmsft/moby,bearstech/moby,cpuguy83/docker,nghiant2710/docker,LaynePeng/docker,Morsicus/docker,Altiscale/docker,mikebrow/docker,dccurtis/docker,kolyshkin/docker,Mashimiao/docker,Mashimiao/docker,menglingwei/denverdino.github.io,cpuguy83/docker,mtesselH/docker,rhatdan/storage,Syntaxide/docker,runcom/docker,wenchma/docker,dccurtis/docker,rillig/docker.github.io,rhatdan/docker,shin-/docker.github.io,rremer/moby,mike1729/docker,unclejack/docker,q384566678/docker,stainboy/docker,naveed-jamil-tenpearls/moby,dmcgowan/docker,resin-io/docker,mathewkoshy493/docker,mkumatag/docker,anweiss/docker.github.io,ndeloof/docker,xiekeyang/docker,docker-zh/docker.github.io,gdevillele/docker.github.io,sanjeo/docker,sean-jc/docker,endophage/docker,13W/docker,ffoysal/docker,afein/docker,asbjornenge/docker,yasiramin10p/moby,fcrisciani/docker,SvenDowideit/docker,Mokolea/docker,tophj-ibm/moby,moul/docker,lixiaobing1/docker,q384566678/docker,containers/storage,anweiss/docker.github.io,isubuz/docker,crosbymichael/docker,sterchelen/docker,rkazak/docker,gjaskiewicz/moby,tmp6154/docker,whuwxl/docker,bonczj/moby-json-file-logger,eskaaren/docker,mikedougherty/docker,amatsus/docker,sarnautov/moby,flavio/docker,xiaods/docker,dmcgowan/docker,moby/moby,jzwlqx/denverdino.github.io,tkopczynski/docker,anujbahuguna/docker,tonistiigi/docker,darrenstahlmsft/moby,DoraALin/docker,kojiromike/docker,scotttlin/docker,mixja/docker,shhsu/docker,docker-zh/docker.github.io