Fixes #2646
Fixes #2646

Pass NULL in the host parameter of grpc_channel_create_call

dklempner/grpc,andrewpollock/grpc,kpayson64/grpc,thunderboltsid/grpc,ppietrasa/grpc,carl-mastrangelo/grpc,Crevil/grpc,andrewpollock/grpc,greasypizza/grpc,rjshade/grpc,Vizerai/grpc,carl-mastrangelo/grpc,perumaalgoog/grpc,msmania/grpc,jcanizales/grpc,yang-g/grpc,makdharma/grpc,royalharsh/grpc,jboeuf/grpc,rjshade/grpc,daniel-j-born/grpc,kpayson64/grpc,MakMukhi/grpc,geffzhang/grpc,ctiller/grpc,jcanizales/grpc,daniel-j-born/grpc,donnadionne/grpc,apolcyn/grpc,kpayson64/grpc,fuchsia-mirror/third_party-grpc,ejona86/grpc,thinkerou/grpc,7anner/grpc,chrisdunelm/grpc,kpayson64/grpc,y-zeng/grpc,nicolasnoble/grpc,murgatroid99/grpc,7anner/grpc,pszemus/grpc,carl-mastrangelo/grpc,nicolasnoble/grpc,Vizerai/grpc,mehrdada/grpc,sreecha/grpc,apolcyn/grpc,deepaklukose/grpc,pszemus/grpc,grpc/grpc,y-zeng/grpc,donnadionne/grpc,dklempner/grpc,adelez/grpc,malexzx/grpc,philcleveland/grpc,sreecha/grpc,philcleveland/grpc,baylabs/grpc,geffzhang/grpc,ipylypiv/grpc,bogdandrutu/grpc,geffzhang/grpc,chrisdunelm/grpc,dgquintas/grpc,pszemus/grpc,mehrdada/grpc,yugui/grpc,malexzx/grpc,infinit/grpc,makdharma/grpc,quizlet/grpc,andrewpollock/grpc,baylabs/grpc,yugui/grpc,pmarks-net/grpc,Crevil/grpc,yang-g/grpc,philcleveland/grpc,jboeuf/grpc,zhimingxie/grpc,a11r/grpc,quizlet/grpc,deepaklukose/grpc,firebase/grpc,thinkerou/grpc,infinit/grpc,grani/grpc,thinkerou/grpc,kumaralokgithub/grpc,adelez/grpc,yugui/grpc,msmania/grpc,stanley-cheung/grpc,chrisdunelm/grpc,malexzx/grpc,firebase/grpc,ppietrasa/grpc,carl-mastrangelo/grpc,adelez/grpc,jboeuf/grpc,a11r/grpc,7anner/grpc,Crevil/grpc,malexzx/grpc,jboeuf/grpc,ncteisen/grpc,royalharsh/grpc,kumaralokgithub/grpc,ejona86/grpc,pmarks-net/grpc,matt-kwong/grpc,apolcyn/grpc,soltanmm/grpc,wcevans/grpc,PeterFaiman/ruby-grpc-minimal,pszemus/grpc,grani/grpc,kriswuollett/grpc,baylabs/grpc,sreecha/grpc,vjpai/grpc,a-veitch/grpc,apolcyn/grpc,deepaklukose/grpc,makdharma/grpc,soltanmm-google/grpc,thunderboltsid/grpc,murgatroid99/grpc,jtattermusch/grpc,thinkerou/grpc,Crevil/grpc,andrewpollock/grpc,thinkerou/grpc,Vizerai/grpc,y-zeng/grpc,firebase/grpc,greasypizza/grpc,baylabs/grpc,quizlet/grpc,adelez/grpc,kumaralokgithub/grpc,ncteisen/grpc,kskalski/grpc,grpc/grpc,grani/grpc,jcanizales/grpc,ejona86/grpc,tengyifei/grpc,jboeuf/grpc,tengyifei/grpc,jboeuf/grpc,sreecha/grpc,stanley-cheung/grpc,baylabs/grpc,baylabs/grpc,ncteisen/grpc,jtattermusch/grpc,podsvirov/grpc,ejona86/grpc,rjshade/grpc,carl-mastrangelo/grpc,vsco/grpc,murgatroid99/grpc,adelez/grpc,grani/grpc,PeterFaiman/ruby-grpc-minimal,vjpai/grpc,bogdandrutu/grpc,matt-kwong/grpc,jcanizales/grpc,MakMukhi/grpc,daniel-j-born/grpc,kumaralokgithub/grpc,deepaklukose/grpc,greasypizza/grpc,msmania/grpc,soltanmm/grpc,MakMukhi/grpc,PeterFaiman/ruby-grpc-minimal,soltanmm-google/grpc,quizlet/grpc,baylabs/grpc,firebase/grpc,mehrdada/grpc,dgquintas/grpc,philcleveland/grpc,yongni/grpc,yongni/grpc,malexzx/grpc,donnadionne/grpc,vsco/grpc,hstefan/grpc,soltanmm-google/grpc,nicolasnoble/grpc,arkmaxim/grpc,dklempner/grpc,tengyifei/grpc,perumaalgoog/grpc,grpc/grpc,vsco/grpc,Vizerai/grpc,nicolasnoble/grpc,kriswuollett/grpc,geffzhang/grpc,jtattermusch/grpc,kumaralokgithub/grpc,a-veitch/grpc,pmarks-net/grpc,quizlet/grpc,dgquintas/grpc,a-veitch/grpc,ctiller/grpc,chrisdunelm/grpc,yugui/grpc,LuminateWireless/grpc,donnadionne/grpc,sreecha/grpc,thinkerou/grpc,dgquintas/grpc,adelez/grpc,murgatroid99/grpc,grpc/grpc,yang-g/grpc,firebase/grpc,Crevil/grpc,Vizerai/grpc,bogdandrutu/grpc,carl-mastrangelo/grpc,jboeuf/grpc,murgatroid99/grpc,ncteisen/grpc,yugui/grpc,zhimingxie/grpc,hstefan/grpc,ppietrasa/grpc,ncteisen/grpc,ipylypiv/grpc,fuchsia-mirror/third_party-grpc,kskalski/grpc,philcleveland/grpc,makdharma/grpc,wcevans/grpc,donnadionne/grpc,yongni/grpc,apolcyn/grpc,grpc/grpc,kpayson64/grpc,zhimingxie/grpc,infinit/grpc,malexzx/grpc,kriswuollett/grpc,royalharsh/grpc,andrewpollock/grpc,donnadionne/grpc,hstefan/grpc,dklempner/grpc,a-veitch/grpc,ipylypiv/grpc,vsco/grpc,dgquintas/grpc,7anner/grpc,thinkerou/grpc,zhimingxie/grpc,rjshade/grpc,stanley-cheung/grpc,pszemus/grpc,jtattermusch/grpc,wcevans/grpc,a-veitch/grpc,dklempner/grpc,ncteisen/grpc,andrewpollock/grpc,jboeuf/grpc,nicolasnoble/grpc,fuchsia-mirror/third_party-grpc,thunderboltsid/grpc,nicolasnoble/grpc,matt-kwong/grpc,grpc/grpc,infinit/grpc,matt-kwong/grpc,fuchsia-mirror/third_party-grpc,thinkerou/grpc,royalharsh/grpc,baylabs/grpc,ejona86/grpc,sreecha/grpc,grpc/grpc,yongni/grpc,kumaralokgithub/grpc,a-veitch/grpc,podsvirov/grpc,firebase/grpc,royalharsh/grpc,greasypizza/grpc,ppietrasa/grpc,muxi/grpc,a11r/grpc,tengyifei/grpc,adelez/grpc,grani/grpc,nicolasnoble/grpc,malexzx/grpc,yang-g/grpc,perumaalgoog/grpc,LuminateWireless/grpc,hstefan/grpc,royalharsh/grpc,infinit/grpc,ppietrasa/grpc,mehrdada/grpc,simonkuang/grpc,tengyifei/grpc,a11r/grpc,MakMukhi/grpc,deepaklukose/grpc,mehrdada/grpc,infinit/grpc,stanley-cheung/grpc,firebase/grpc,yugui/grpc,zhimingxie/grpc,murgatroid99/grpc,daniel-j-born/grpc,pmarks-net/grpc,bogdandrutu/grpc,philcleveland/grpc,muxi/grpc,thinkerou/grpc,stanley-cheung/grpc,royalharsh/grpc,muxi/grpc,arkmaxim/grpc,pszemus/grpc,pszemus/grpc,kriswuollett/grpc,kumaralokgithub/grpc,yang-g/grpc,simonkuang/grpc,PeterFaiman/ruby-grpc-minimal,PeterFaiman/ruby-grpc-minimal,kskalski/grpc,thunderboltsid/grpc,greasypizza/grpc,jtattermusch/grpc,msmania/grpc,ncteisen/grpc,kumaralokgithub/grpc,yongni/grpc,arkmaxim/grpc,7anner/grpc,mehrdada/grpc,makdharma/grpc,msmania/grpc,ctiller/grpc,msmania/grpc,andrewpollock/grpc,vsco/grpc,jboeuf/grpc,adelez/grpc,murgatroid99/grpc,Vizerai/grpc,yang-g/grpc,LuminateWireless/grpc,makdharma/grpc,nicolasnoble/grpc,simonkuang/grpc,arkmaxim/grpc,LuminateWireless/grpc,muxi/grpc,pmarks-net/grpc,sreecha/grpc,deepaklukose/grpc,podsvirov/grpc,muxi/grpc,soltanmm/grpc,perumaalgoog/grpc,hstefan/grpc,kriswuollett/grpc,sreecha/grpc,geffzhang/grpc,kriswuollett/grpc,donnadionne/grpc,ppietrasa/grpc,a-veitch/grpc,firebase/grpc,mehrdada/grpc,jtattermusch/grpc,mehrdada/grpc,ipylypiv/grpc,mehrdada/grpc,podsvirov/grpc,donnadionne/grpc,dgquintas/grpc,hstefan/grpc,rjshade/grpc,rjshade/grpc,arkmaxim/grpc,msmania/grpc,kpayson64/grpc,kpayson64/grpc,royalharsh/grpc,grani/grpc,mehrdada/grpc,PeterFaiman/ruby-grpc-minimal,andrewpollock/grpc,MakMukhi/grpc,Crevil/grpc,soltanmm/grpc,quizlet/grpc,perumaalgoog/grpc,mehrdada/grpc,ncteisen/grpc,kskalski/grpc,yang-g/grpc,dklempner/grpc,pmarks-net/grpc,pszemus/grpc,wcevans/grpc,perumaalgoog/grpc,PeterFaiman/ruby-grpc-minimal,matt-kwong/grpc,stanley-cheung/grpc,kskalski/grpc,ejona86/grpc,murgatroid99/grpc,muxi/grpc,Crevil/grpc,muxi/grpc,ipylypiv/grpc,ipylypiv/grpc,soltanmm-google/grpc,arkmaxim/grpc,royalharsh/grpc,ejona86/grpc,jcanizales/grpc,grani/grpc,podsvirov/grpc,tengyifei/grpc,a11r/grpc,vsco/grpc,kskalski/grpc,ctiller/grpc,chrisdunelm/grpc,fuchsia-mirror/third_party-grpc,kskalski/grpc,vjpai/grpc,soltanmm-google/grpc,chrisdunelm/grpc,kriswuollett/grpc,deepaklukose/grpc,carl-mastrangelo/grpc,philcleveland/grpc,sreecha/grpc,fuchsia-mirror/third_party-grpc,daniel-j-born/grpc,grani/grpc,a-veitch/grpc,thunderboltsid/grpc,jcanizales/grpc,sreecha/grpc,podsvirov/grpc,bogdandrutu/grpc,msmania/grpc,chrisdunelm/grpc,apolcyn/grpc,zhimingxie/grpc,pszemus/grpc,nicolasnoble/grpc,apolcyn/grpc,LuminateWireless/grpc,grpc/grpc,Crevil/grpc,kriswuollett/grpc,ctiller/grpc,pmarks-net/grpc,jboeuf/grpc,ncteisen/grpc,simonkuang/grpc,vjpai/grpc,thunderboltsid/grpc,grani/grpc,yongni/grpc,matt-kwong/grpc,kpayson64/grpc,fuchsia-mirror/third_party-grpc,wcevans/grpc,ppietrasa/grpc,donnadionne/grpc,soltanmm-google/grpc,jtattermusch/grpc,LuminateWireless/grpc,soltanmm-google/grpc,kriswuollett/grpc,kskalski/grpc,thunderboltsid/grpc,yugui/grpc,hstefan/grpc,murgatroid99/grpc,nicolasnoble/grpc,sreecha/grpc,jtattermusch/grpc,kpayson64/grpc,vjpai/grpc,greasypizza/grpc,jcanizales/grpc,y-zeng/grpc,daniel-j-born/grpc,MakMukhi/grpc,jtattermusch/grpc,pszemus/grpc,Vizerai/grpc,chrisdunelm/grpc,arkmaxim/grpc,stanley-cheung/grpc,quizlet/grpc,bogdandrutu/grpc,dgquintas/grpc,carl-mastrangelo/grpc,kpayson64/grpc,PeterFaiman/ruby-grpc-minimal,chrisdunelm/grpc,yugui/grpc,geffzhang/grpc,simonkuang/grpc,PeterFaiman/ruby-grpc-minimal,a-veitch/grpc,ejona86/grpc,tengyifei/grpc,muxi/grpc,carl-mastrangelo/grpc,Vizerai/grpc,dgquintas/grpc,7anner/grpc,stanley-cheung/grpc,Vizerai/grpc,jcanizales/grpc,baylabs/grpc,a11r/grpc,thinkerou/grpc,ncteisen/grpc,firebase/grpc,infinit/grpc,vsco/grpc,zhimingxie/grpc,dgquintas/grpc,quizlet/grpc,simonkuang/grpc,vjpai/grpc,pmarks-net/grpc,tengyifei/grpc,zhimingxie/grpc,wcevans/grpc,greasypizza/grpc,grpc/grpc,stanley-cheung/grpc,dgquintas/grpc,nicolasnoble/grpc,ncteisen/grpc,zhimingxie/grpc,apolcyn/grpc,y-zeng/grpc,yongni/grpc,kpayson64/grpc,yongni/grpc,nicolasnoble/grpc,hstefan/grpc,thinkerou/grpc,vsco/grpc,MakMukhi/grpc,pmarks-net/grpc,tengyifei/grpc,PeterFaiman/ruby-grpc-minimal,ctiller/grpc,Vizerai/grpc,arkmaxim/grpc,muxi/grpc,podsvirov/grpc,rjshade/grpc,jtattermusch/grpc,dklempner/grpc,a11r/grpc,adelez/grpc,carl-mastrangelo/grpc,geffzhang/grpc,rjshade/grpc,jboeuf/grpc,makdharma/grpc,yang-g/grpc,MakMukhi/grpc,soltanmm-google/grpc,soltanmm/grpc,chrisdunelm/grpc,jboeuf/grpc,LuminateWireless/grpc,vsco/grpc,ncteisen/grpc,a11r/grpc,infinit/grpc,simonkuang/grpc,pszemus/grpc,sreecha/grpc,7anner/grpc,ejona86/grpc,deepaklukose/grpc,chrisdunelm/grpc,podsvirov/grpc,a11r/grpc,soltanmm/grpc,daniel-j-born/grpc,muxi/grpc,vjpai/grpc,ipylypiv/grpc,deepaklukose/grpc,dklempner/grpc,donnadionne/grpc,firebase/grpc,perumaalgoog/grpc,thunderboltsid/grpc,infinit/grpc,philcleveland/grpc,firebase/grpc,geffzhang/grpc,thinkerou/grpc,murgatroid99/grpc,y-zeng/grpc,matt-kwong/grpc,ctiller/grpc,jtattermusch/grpc,Vizerai/grpc,perumaalgoog/grpc,makdharma/grpc,soltanmm/grpc,pszemus/grpc,LuminateWireless/grpc,ppietrasa/grpc,vjpai/grpc,makdharma/grpc,grpc/grpc,geffzhang/grpc,ctiller/grpc,soltanmm/grpc,mehrdada/grpc,yugui/grpc,dklempner/grpc,vjpai/grpc,ctiller/grpc,muxi/grpc,ctiller/grpc,yang-g/grpc,apolcyn/grpc,firebase/grpc,ipylypiv/grpc,ctiller/grpc,Crevil/grpc,vjpai/grpc,perumaalgoog/grpc,ejona86/grpc,kumaralokgithub/grpc,carl-mastrangelo/grpc,greasypizza/grpc,ejona86/grpc,yongni/grpc,fuchsia-mirror/third_party-grpc,donnadionne/grpc,y-zeng/grpc,grpc/grpc,greasypizza/grpc,matt-kwong/grpc,wcevans/grpc,ejona86/grpc,jtattermusch/grpc,arkmaxim/grpc,rjshade/grpc,wcevans/grpc,MakMukhi/grpc,thunderboltsid/grpc,vjpai/grpc,muxi/grpc,podsvirov/grpc,ppietrasa/grpc,stanley-cheung/grpc,malexzx/grpc,grpc/grpc,kskalski/grpc,ipylypiv/grpc,7anner/grpc,fuchsia-mirror/third_party-grpc,simonkuang/grpc,malexzx/grpc,donnadionne/grpc,msmania/grpc,quizlet/grpc,matt-kwong/grpc,bogdandrutu/grpc,wcevans/grpc,bogdandrutu/grpc,fuchsia-mirror/third_party-grpc,stanley-cheung/grpc,bogdandrutu/grpc,soltanmm/grpc,LuminateWireless/grpc,y-zeng/grpc,stanley-cheung/grpc,daniel-j-born/grpc,vjpai/grpc,simonkuang/grpc,jcanizales/grpc,y-zeng/grpc,philcleveland/grpc,andrewpollock/grpc,soltanmm-google/grpc,7anner/grpc,hstefan/grpc,ctiller/grpc,carl-mastrangelo/grpc,daniel-j-born/grpc,dgquintas/grpc