api/server: fix stray import in container_routes.go
api/server: fix stray import in container_routes.go

This import was left behind due to some PR's being merged, both
affecting the imports that were used.

Signed-off-by: Sebastiaan van Stijn <64b2b6d12bfe4baae7dad3d018f8cbf6b0e7a044@gone.nl>

trebonian/docker,Mokolea/docker,Ramzec/docker,Mokolea/docker,Mokolea/docker,trebonian/docker,mahak/docker,moul/docker,jimjag/docker,Ramzec/docker,Ramzec/docker,moby/moby,moul/docker,konstruktoid/docker-upstream,thaJeztah/docker,nawawi/docker,nawawi/docker,vdemeester/docker,jimjag/docker,moby/moby,trebonian/docker,mahak/docker,thaJeztah/docker,mahak/docker,nawawi/docker,konstruktoid/docker-upstream,moby/moby,moul/docker,thaJeztah/docker,konstruktoid/docker-upstream,cpuguy83/docker,vdemeester/docker,cpuguy83/docker,nawawi/docker,konstruktoid/docker-upstream,mahak/docker,jimjag/docker,moul/docker,trebonian/docker,Mokolea/docker,thaJeztah/docker,cpuguy83/docker,Ramzec/docker,cpuguy83/docker,moby/moby,vdemeester/docker,jimjag/docker