ignore del groups failure before subscriber test

Change-Id: I0ddd270ee40e4d9a2215fcc92782022d927356f4
diff --git a/src/test/cordSubscriber/cordSubscriberTest.py b/src/test/cordSubscriber/cordSubscriberTest.py
index 4d6c7e2..d585323 100644
--- a/src/test/cordSubscriber/cordSubscriberTest.py
+++ b/src/test/cordSubscriber/cordSubscriberTest.py
@@ -382,11 +382,12 @@
       def ovs_cleanup(cls):
             ##For every test case, delete all the OVS groups
             cmd = 'ovs-ofctl del-groups br-int -OOpenFlow11 >/dev/null 2>&1'
-            cord_test_shell(cmd)
-            ##Since olt config is used for this test, we just fire a careless local cmd as well
             try:
+                  cord_test_shell(cmd)
+                  ##Since olt config is used for this test, we just fire a careless local cmd as well
                   os.system(cmd)
-            except: pass
+            finally:
+                  return
 
       def onos_aaa_load(self):
             if self.aaa_loaded: