Unhard-coded 'message_queue:port:${_param:rabbitmq_port}'

Change-Id: I9c57a01b4e9f3b5cc03a7618ac8b7af1d227ab76
diff --git a/aodh/server/cluster.yml b/aodh/server/cluster.yml
index 6d756d1..444050a 100644
--- a/aodh/server/cluster.yml
+++ b/aodh/server/cluster.yml
@@ -14,6 +14,7 @@
     galera_ssl_enabled: False
     openstack_rabbitmq_x509_enabled: False
     rabbitmq_ssl_enabled: False
+    openstack_rabbitmq_port: 5672
   linux:
     system:
       cron:
@@ -59,7 +60,7 @@
         protocol: ${_param:cluster_internal_protocol}
       message_queue:
         engine: rabbitmq
-        port: 5672
+        port: ${_param:openstack_rabbitmq_port}
         user: openstack
         password: ${_param:rabbitmq_openstack_password}
         virtual_host: '/openstack'