Revert "Fixing voltha system tests to account for IGMP"

This reverts commit ddb1e06a6b51eeca00ac6b5056af823466c23e1a.

Reason for revert: commit has been merged in voltha-system-tests repo

Change-Id: I13441c580435b1b55032e4d17e639317f6493e13
diff --git a/jjb/voltha-scale.yaml b/jjb/voltha-scale.yaml
index f4252a6..a1a94de 100644
--- a/jjb/voltha-scale.yaml
+++ b/jjb/voltha-scale.yaml
@@ -96,7 +96,6 @@
           onosReplicas: 3
           atomixReplicas: 3
           extraHelmFlags: '--set defaults.rw_core.timeout=30s '
-          volthaSystemTestsChange:  'refs/changes/78/20378/8'
 
       - 'voltha-scale-measurements':
           name: 'voltha-scale-measurements-master-1-16-32-tt-subscribers'
@@ -115,7 +114,6 @@
           onosReplicas: 3
           atomixReplicas: 3
           extraHelmFlags: '--set defaults.rw_core.timeout=30s '
-          volthaSystemTestsChange:  'refs/changes/78/20378/8'
 
       # jobs for DT with 512 ONUs with a 8 openonu-adapters and clustered ONOS.
       - 'voltha-scale-measurements':