driver/swift: treat empty object list as a PathNotFoundError
driver/swift: treat empty object list as a PathNotFoundError

Swift returns an empty object list when trying to read a non-existing object path, treat it as a
PathNotFoundError when trying to list a non existing virtual directory.

Signed-off-by: David li <0c162413851a7a5800fbda72661f46bad18cc476@hpe.com>

andrewnguyen/distribution,huamai-io/distribution,denverdino/denverdino.github.io,aduermael/docker.github.io,shubheksha/docker.github.io,dobril-stanga/distribution,BrianBland/distribution,andrewnguyen/distribution,JimGalasyn/docker.github.io,mikebrow/distribution,BSWANG/denverdino.github.io,johnstep/docker.github.io,shubheksha/docker.github.io,duglin/distribution,denverdino/docker.github.io,docker-zh/docker.github.io,johnstep/docker.github.io,joeuo/docker.github.io,joeuo/docker.github.io,londoncalling/docker.github.io,konstruktoid/distribution,yuwaMSFT2/distribution,gdevillele/docker.github.io,genedock/distribution,schu/distribution,jzwlqx/denverdino.github.io,sadlil/distribution,hopkings2008/distribution,alexisbellido/docker.github.io,JimGalasyn/docker.github.io,aduermael/docker.github.io,menglingwei/denverdino.github.io,kmala/distribution,aaronlehmann/distribution,stevvooe/distribution,rbarlow/distribution,gdevillele/docker.github.io,docker/docker.github.io,shin-/docker.github.io,shubheksha/docker.github.io,nwt/distribution,menglingwei/denverdino.github.io,stevvooe/distribution,anweiss/docker.github.io,xiekeyang/distribution,gdevillele/docker.github.io,Seb-Solon/distribution,yuwaMSFT2/distribution,xiekeyang/distribution,mattrgreen/distribution,londoncalling/docker.github.io,aduermael/docker.github.io,bdwill/docker.github.io,gdevillele/docker.github.io,joeuo/docker.github.io,thaJeztah/docker.github.io,danix800/docker.github.io,cyli/distribution,harrisonfeng/distribution,denverdino/denverdino.github.io,thaJeztah/docker.github.io,docker/docker.github.io,runcom/distribution,phiroict/docker,sanscontext/docker.github.io,joaofnfernandes/docker.github.io,konstruktoid/distribution,joaofnfernandes/docker.github.io,miminar/distribution,dmcgowan/distribution,liubin/distribution,BSWANG/denverdino.github.io,jlhawn/distribution,bdwill/docker.github.io,mbentley/distribution,joaofnfernandes/docker.github.io,shyr/distribution,mbentley/distribution,thaJeztah/distribution,docker/docker.github.io,nevermosby/distribution,jzwlqx/distribution,alexisbellido/docker.github.io,konnase/distribution,jlhawn/distribution,denverdino/docker.github.io,phiroict/docker,denverdino/docker.github.io,hopkings2008/distribution,thaJeztah/docker.github.io,shin-/docker.github.io,anweiss/docker.github.io,anweiss/docker.github.io,bdwill/docker.github.io,troy0820/docker.github.io,londoncalling/docker.github.io,denverdino/distribution,BrickXu/distribution,troy0820/docker.github.io,johnstep/docker.github.io,sebrandon1/distribution,joeuo/docker.github.io,runcom/distribution,vdemeester/distribution,duglin/distribution,LuisBosquez/docker.github.io,denverdino/denverdino.github.io,LuisBosquez/docker.github.io,thaJeztah/docker.github.io,LuisBosquez/docker.github.io,JimGalasyn/docker.github.io,rbarlow/distribution,menglingwei/denverdino.github.io,anweiss/docker.github.io,danix800/docker.github.io,jwhonce/distribution,genedock/distribution,djenriquez/distribution,johnstep/docker.github.io,LuisBosquez/docker.github.io,docker-zh/docker.github.io,troy0820/docker.github.io,gdevillele/docker.github.io,menglingwei/denverdino.github.io,shubheksha/docker.github.io,shyr/distribution,estesp/distribution,jzwlqx/denverdino.github.io,docker/distribution,liubin/distribution,docker-zh/docker.github.io,phiroict/docker,danix800/docker.github.io,docker/distribution,miminar/distribution,shin-/docker.github.io,jzwlqx/denverdino.github.io,denverdino/denverdino.github.io,cezarsa/distribution,sergeyfd/distribution,sanscontext/docker.github.io,jzwlqx/distribution,sanscontext/docker.github.io,docker/docker.github.io,sadlil/distribution,phiroict/docker,rillig/docker.github.io,denverdino/docker.github.io,noxiouz/distribution,BSWANG/denverdino.github.io,troy0820/docker.github.io,bdwill/docker.github.io,manoj535/distribution,Seb-Solon/distribution,docker/docker.github.io,sanscontext/docker.github.io,harrisonfeng/distribution,denverdino/denverdino.github.io,cezarsa/distribution,denverdino/distribution,djenriquez/distribution,aprajshekhar/distribution,manoj535/distribution,schu/distribution,spacexnice/distribution,mattrgreen/distribution,alexisbellido/docker.github.io,shin-/docker.github.io,denverdino/docker.github.io,BSWANG/denverdino.github.io,nevermosby/distribution,rillig/docker.github.io,sergeyfd/distribution,docker-zh/docker.github.io,joaofnfernandes/docker.github.io,sanscontext/docker.github.io,huamai-io/distribution,RichardScothern/distribution,BSWANG/denverdino.github.io,LuisBosquez/docker.github.io,aprajshekhar/distribution,bdwill/docker.github.io,nwt/distribution,mikebrow/distribution,dmcgowan/distribution,thaJeztah/distribution,rillig/docker.github.io,menglingwei/denverdino.github.io,BrianBland/distribution,shin-/docker.github.io,danix800/docker.github.io,alexisbellido/docker.github.io,deis/distribution,alexisbellido/docker.github.io,rillig/docker.github.io,JimGalasyn/docker.github.io,noxiouz/distribution,joeuo/docker.github.io,johnstep/docker.github.io,RichardScothern/distribution,jzwlqx/denverdino.github.io,kmala/distribution,dobril-stanga/distribution,konnase/distribution,moxiegirl/distribution,londoncalling/docker.github.io,jwhonce/distribution,anweiss/docker.github.io,jzwlqx/denverdino.github.io,deis/distribution,BrickXu/distribution,shubheksha/docker.github.io,sebrandon1/distribution,moxiegirl/distribution,phiroict/docker,JimGalasyn/docker.github.io,joaofnfernandes/docker.github.io,spacexnice/distribution,aduermael/docker.github.io,docker-zh/docker.github.io,estesp/distribution,thaJeztah/docker.github.io,londoncalling/docker.github.io,vdemeester/distribution,cyli/distribution,aaronlehmann/distribution