client: remove unused Platform field from configWrapper

This field was added in 7a9cb29fb980c0ab3928272cdc24c7089b2fcf64,
but appears to be unused, so removing it.

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

client/container_create.go

@@ -16,7 +16,6 @@ type configWrapper struct {
 	*container.Config
 	HostConfig       *container.HostConfig
 	NetworkingConfig *network.NetworkingConfig
-	Platform         *specs.Platform
 }
 
 // ContainerCreate creates a new container based on the given configuration.