library/roles/iptables/templates/iptables-rules.v4.j2: The tomcat cluster rules need more flexibility.

iptables/templates/iptables-rules.v4.j2

@@ -175,6 +175,9 @@
 # tomcat cluster
 -A INPUT -m pkttype --pkt-type multicast -d {{ tomcat_cluster_multicast_addr }} -j ACCEPT
 -A INPUT -m state --state NEW -p tcp -m tcp --dport {{ tomcat_cluster_multicast_port }} -j ACCEPT
+{% if tomcat_cluster_multicast_net is defined %}
+-A INPUT -d {{ tomcat_cluster_multicast_net }} -j ACCEPT
+{% endif %}
 {% endif %}
 {% if ganglia_enabled is defined %}
 {% if ganglia_enabled %}