Fix in endpoint Info() method
Fix in endpoint Info() method

- Make sure to return the proper value for the
  EndpointInfo interface in case of nil implementer

Signed-off-by: Alessandro Boch <5bd2eb5b6f60921d9a2b9cb6a0a86bb947f3d361@docker.com>

paralin/docker,mahak/docker,jthelin/docker,nawawi/docker,jimjag/docker,nalind/docker,thaJeztah/docker,moul/docker,thaJeztah/docker,yosifkit/docker,Mokolea/docker,moul/docker,cpuguy83/docker,moul/docker,bearstech/moby,djs55/docker,djs55/docker,AkihiroSuda/docker,moul/docker,Ramzec/docker,flavio/docker,konstruktoid/docker-upstream,cpuguy83/docker,AkihiroSuda/docker,vdemeester/docker,AkihiroSuda/docker,jameszhan/docker,konstruktoid/docker-upstream,paralin/docker,nalind/docker,flavio/docker,Mokolea/docker,nalind/docker,bearstech/moby,yosifkit/docker,bearstech/moby,Mokolea/docker,trebonian/docker,mahak/docker,paralin/docker,vdemeester/docker,moby/moby,docker/docker,gnailuy/docker,nawawi/docker,djs55/docker,jthelin/docker,vdemeester/docker,flavio/docker,konstruktoid/docker-upstream,thaJeztah/docker,cpuguy83/docker,yosifkit/docker,trebonian/docker,Ramzec/docker,trebonian/docker,yosifkit/docker,mahak/docker,moby/moby,docker/docker,gnailuy/docker,jameszhan/docker,docker/docker,cpuguy83/docker,mahak/docker,paralin/docker,AkihiroSuda/docker,Mokolea/docker,moby/moby,moby/moby,gnailuy/docker,konstruktoid/docker-upstream,trebonian/docker,thaJeztah/docker,jimjag/docker,Ramzec/docker,nawawi/docker,jimjag/docker,Ramzec/docker,gnailuy/docker,nawawi/docker,jimjag/docker,nalind/docker,flavio/docker,bearstech/moby,jameszhan/docker