Sync can_send_version() helper from oslo-incubator.

This patch syncs a helper method added to the RpcProxy class from
oslo-incubator.

Change-Id: Ifd374245c15cef7af7487a19935193b590c1bd4e
Merge "Sync can_send_version() helper from oslo-incubator."
Merge remote-tracking branch 'm_src_repo/citrix-fixes' into build-temp