Fix to allow use of custom images in verification jobs

Change-Id: I9eb24cc4a4056290147ce0e0889f4b6cdd953e5a
diff --git a/jjb/pipeline/voltha-openonu-go-tests.groovy b/jjb/pipeline/voltha-openonu-go-tests.groovy
index cb9a0c2..d63b795 100755
--- a/jjb/pipeline/voltha-openonu-go-tests.groovy
+++ b/jjb/pipeline/voltha-openonu-go-tests.groovy
@@ -39,7 +39,7 @@
     CONFIG_SADIS="external"
     BBSIM_CFG="configs/bbsim-sadis-att.yaml"
     ROBOT_MISC_ARGS="-d $WORKSPACE/RobotLogs"
-    EXTRA_HELM_FLAGS=" --set defaults.image_registry=mirror.registry.opennetworking.org/ "
+    EXTRA_HELM_FLAGS=" --set global.image_registry=mirror.registry.opennetworking.org/ "
   }
   stages {
     stage('Clone kind-voltha') {