Fixing kind-voltha test for 2.7 branch

Change-Id: I32cc5e6c84401385e87d159e90de525b74de2c31
diff --git a/jjb/verify/kind-voltha.yaml b/jjb/verify/kind-voltha.yaml
index cf7e1ff..8b43798 100644
--- a/jjb/verify/kind-voltha.yaml
+++ b/jjb/verify/kind-voltha.yaml
@@ -21,3 +21,4 @@
           pipeline-script: 'voltha/voltha-2.7/voltha-bbsim-tests.groovy'
           name-extension: '-2.7'
           override-branch: 'voltha-2.7'
+          kindVolthaChange: '$GERRIT_REFSPEC'