specify a REFSPEC

Change-Id: I1ebe05bdc0339e5d5a436202cc0a256888af5b6f
diff --git a/jjb/onos/onos-buck-gerrit.yaml b/jjb/onos/onos-buck-gerrit.yaml
index 48d42ce..46401e8 100644
--- a/jjb/onos/onos-buck-gerrit.yaml
+++ b/jjb/onos/onos-buck-gerrit.yaml
@@ -10,8 +10,8 @@
       script-path: tools/build/jenkins/onos-buck-gerrit
       scm:
         - lf-infra-gerrit-scm:
-            git-url: '$GIT_URL/$PROJECT'
-            refspec: '$GERRIT_REFSPEC'
+            git-url: '$GIT_URL/onos'
+            refspec: 'master'
             branch: 'master'
             submodule-recursive: '{submodule-recursive}'
             choosing-strategy: gerrit