Fix: do not install group table rules if ARP mode set as proxy mode

Change-Id: I7f9a44b3c0d2b02d6bdd9431863eb0b23fd4d201

Author: gunine

apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/impl/OpenstackSwitchingArpHandler.java

@@ -944,6 +944,11 @@ private void processNetworkRemoval(OpenstackNetworkEvent event) {
         }
 
         private void setVnetArpRule(Network network, boolean install) {
+
+            if (ARP_PROXY_MODE.equals(getArpMode())) {
+                return;
+            }
+
             String netId = network.getId();
             NetworkType netType = network.getNetworkType();