api/server/router/grpc: fix some nits in NewRouter()
api/server/router/grpc: fix some nits in NewRouter()

These were changes I drafted when reviewing 7c731e02a980666e262c68d4995f5643b6ffae30,
and had these stashed in my local git;

- rename receiver to prevent "unconsistent receiver name" warnings
- make NewRouter() slightly more idiomatic, and wrap the options,
  to make them easier to read.

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

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