Fix simple documentation copy/paste error.
Fix simple documentation copy/paste error.

Signed-off-by: Jan Losinski <577c4104c61edf9f052c616c0c23e67bef4a9955@wh2.tu-dresden.de>

vdemeester/docker-py,funkyfuture/docker-py,vpetersson/docker-py,docker/docker-py,vpetersson/docker-py,youhong316/docker-py,funkyfuture/docker-py,vdemeester/docker-py,docker/docker-py,youhong316/docker-py