Remove deprecated code from VTN synchronizer

Change-Id: Iae6f7d69d6a7be02e676ed856834984bfba87681
diff --git a/xos/synchronizer/steps/sync_onos_netcfg.py b/xos/synchronizer/steps/sync_onos_netcfg.py
index 8156a20..598d782 100644
--- a/xos/synchronizer/steps/sync_onos_netcfg.py
+++ b/xos/synchronizer/steps/sync_onos_netcfg.py
@@ -119,7 +119,12 @@
         # Generate apps->org.opencord.vtn->cordvtn->nodes
         nodes = Node.objects.all()
         for node in nodes:
-            nodeip = socket.gethostbyname(node.name)
+            try:
+                nodeip = socket.gethostbyname(node.name)
+            except socket.gaierror:
+                logger.warn("unable to resolve hostname %s: node will not be added to config"
+                            % node.name)
+                continue
 
             try:
                 bridgeId = self.get_node_tag(node, "bridgeId")