Before this change we only ever had the grpc incoming medata set so when
we make a request to a shim or a grpc plugin the namespace is not sent
over the RPC.
I need this for github.com/cpuguy83/systemdshim, and I am sure there are
other use-cases where this would be needed.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
