Comment 20 for bug 1708976

Reviewed: https://review.openstack.org/491350
Committed: https://git.openstack.org/cgit/openstack/puppet-magnum/commit/?id=008810dfbdf5845b79a078813c681fb8b3a03039
Submitter: Jenkins
Branch: master

commit 008810dfbdf5845b79a078813c681fb8b3a03039
Author: ZhongShengping <chdzsp@163.com>
Date: Mon Aug 7 14:02:07 2017 +0800

    Deprecate oslo.messaging rpc_backend option parameter

    Oslo.messaging uses the transport_url to represent the rpc and
    notification messaging driver to use and its full configuration. The
    rpc_backend configuration option is deprecated for removal and
    should not gate oslo.messaging driver configuration options.

    This patch:
    * deprecate rpc_backend
    * remove conditional check
    * update spec tests
    * add release note

    Change-Id: I5bac059b9c06b691a140a6c7c28c766ec66c1bd9
    Closes-Bug: #1708976