Fix iptables for fedmsg on fedimg hosts.

roles/fedmsg/base/templates/endpoints-fedimg.py.j2

@@ -4,6 +4,8 @@ suffix  = 'stg.phx2.fedoraproject.org'
 suffix = 'phx2.fedoraproject.org'
 {% endif %}
 
+# REMEMBER -- if you change these, you need to also change the iptables rules in
+# inventory/groups/fedimg and inventory/groups/fedimsg-stg
 primary_threads = 4
 atomic_threads = 2
 NUM_FEDIMG_PORTS = 2 * ((primary_threads + atomic_threads) + 1)