client: use canonical names for HTTP Headers
client: use canonical names for HTTP Headers

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

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