Fixes for Onos cord instance wrapper restart case.
Add a exception marker for logs with exceptions.

Change-Id: Ic68f15ba777768ab040c89985d7044cdf1867ef7
diff --git a/src/test/utils/CordTestServer.py b/src/test/utils/CordTestServer.py
index 1359850..c302d8c 100644
--- a/src/test/utils/CordTestServer.py
+++ b/src/test/utils/CordTestServer.py
@@ -37,7 +37,7 @@
 
     def __restart_onos(self, node = None, config = None, timeout = 10):
         if self.onos_cord:
-            onos_config = '{}/network-cfg.json'.format(OnosCord.onos_config_dir)
+            onos_config = '{}/network-cfg.json'.format(self.onos_cord.onos_config_dir)
         else:
             onos_config = '{}/network-cfg.json'.format(Onos.host_config_dir)
         if config is None: