Open 4789/udp when using the SDN

roles/openshift_node/defaults/main.yml

@@ -10,3 +10,6 @@ os_firewall_allow:
   port: 10255/tcp
 - service: Openshift kubelet ReadOnlyPort udp
   port: 10255/udp
+- service: OpenShift OVS sdn
+  port: 4789/udp
+  when: openshift.node.use_openshift_sdn | bool