freshmaker: restart fedmsg-hub daemon

'restart fedmsg-hub' handler from restart_services doesn't work, use our
own handler before that fix that one (it's used by many roles, I don't
want to break anything before confirm the issue). And update app config
(add prod fedmsg topic for stage to listen on) to notify the handler.

inventory/group_vars/freshmaker-stg

@@ -2,6 +2,7 @@
 # For app config
 freshmaker_messaging_topic_prefix:
 - org.fedoraproject.stg
+- org.fedoraproject.prod
 
 freshmaker_parsers:
 - freshmaker.parsers.git:GitReceiveParser

roles/freshmaker/base/handlers/main.yml

@@ -0,0 +1,3 @@
+---
+- name: restart fedmsg-hub daemon
+  command: /usr/local/bin/conditional-restart.sh fedmsg-hub python2-fedmsg

roles/freshmaker/base/tasks/main.yml

@@ -34,6 +34,6 @@
     mode: 0440
   notify:
   - restart apache
-  - restart fedmsg-hub
+  - restart fedmsg-hub daemon
   tags:
   - freshmaker