Deprecate rabbit connection params

The rabbit connection parameters have been deprecated in oslo[0] in favor
of transport_url which is provided by oslo::messaging::default.

[0] https://review.openstack.org/#/c/317285/

Change-Id: Ia78fcca898aea28bfe436faa259544f5594a5af6

manifests/messaging/rabbit.pp

@@ -177,6 +177,12 @@ define oslo::messaging::rabbit(
     fail('Unsupported Kombu compression. Possible values are gzip and bz2')
   }
 
+  if !is_service_default($rabbit_hosts) or !is_service_default($rabbit_host) {
+    warning("The oslo_messaging rabbit_host, rabbit_hosts, rabbit_port, rabbit_userid, \
+rabbit_password, rabbit_virtual_host parameters have been deprecated by the \
+[DEFAULT]\transport_url. Please use oslo::messaging::default::transport_url instead.")
+  }
+
   if !is_service_default($rabbit_hosts) {
     $rabbit_hosts_orig = join(any2array($rabbit_hosts), ',')
     if size($rabbit_hosts) > 1 and is_service_default($rabbit_ha_queues) {

manifests/releasenotes/notes/rabbitmq-connection-params-1a8ace0c23e7249e.yaml

@@ -0,0 +1,6 @@
+---
+deprecations:
+  - The rabbitmq connection paramters have been deprecated in favor of
+    transport_url which is provided by the oslo::messaging::default class.
+    This affects, rabbit_host, rabbit_port, rabbit_hosts, rabbit_userid,
+    rabbit_password and rabbit_virtual_host.