Allow sending untagged dhcp traffic from vsgTest if running from subscriber/olt side.

Change-Id: I746be577290e7a508eec71f9f772ecd766638f4b
diff --git a/src/test/vsg/vsgTest.py b/src/test/vsg/vsgTest.py
index affa0e2..551e2a8 100644
--- a/src/test/vsg/vsgTest.py
+++ b/src/test/vsg/vsgTest.py
@@ -147,6 +147,8 @@
         if cls.vcpes_dhcp:
             vcpe_container = 'vcpe-{}-{}'.format(cls.vcpes_dhcp[0]['s_tag'], cls.vcpes_dhcp[0]['c_tag'])
             vcpe_dhcp = 'vcpe0.{}.{}'.format(cls.vcpes_dhcp[0]['s_tag'], cls.vcpes_dhcp[0]['c_tag'])
+            if 'untagged' in cls.vcpes_dhcp[0] and cls.vcpes_dhcp[0]['untagged']:
+                vcpe_dhcp = 'vcpe0'
             vcpe_dhcp_stag = 'vcpe0.{}'.format(cls.vcpes_dhcp[0]['s_tag'])
         cls.vcpe_container = vcpe_container
         cls.vcpe_dhcp = vcpe_dhcp