Remove deprected notification_topics option

notification_topics was deprecated. Now we use
oslo_messaging_notifications.topics option instead [1]

[1] https://docs.openstack.org/oslo.messaging/latest/configuration/opts.html#oslo-messaging-notifications

Change-Id: I9ed3cca6d25d08494e0933a1fb8a9502b07b9775

ansible/roles/aodh/templates/aodh.conf.j2

@@ -3,8 +3,6 @@
 auth_strategy = keystone
 log_dir = /var/log/kolla/aodh
 debug = {{ aodh_logging_debug }}
-notification_topics = notifications
-
 transport_url = {{ rpc_transport_url }}
 
 [api]
@@ -48,3 +46,8 @@ interface = internal
 
 [oslo_messaging_notifications]
 transport_url = {{ notify_transport_url }}
+{% if enable_ceilometer | bool %}
+driver = messagingv2
+topics = notifications
+{% endif %}
+