Add error message to help debug failing test on production machines

Change-Id: I0c9e25843c8d7c6bc4e028fea1a843d0a3da4e02
diff --git a/TestON/drivers/common/cli/onosdriver.py b/TestON/drivers/common/cli/onosdriver.py
index 028ec91..628101c 100755
--- a/TestON/drivers/common/cli/onosdriver.py
+++ b/TestON/drivers/common/cli/onosdriver.py
@@ -2273,6 +2273,7 @@
                     curIp = tmpList[0]
                     self.ip_address = curIp
                     return curIp
+            main.log.warn( "getIpAddr failed to find a public IP address" )
             return localhost
         except Exception:
             main.log.exception( "Uncaught exception" )