Build 'events-rabbitmq' master against Gerrit stable-3.7

Change-Id: Ied1992c2e283461028650561ebe607d079212f0a
diff --git a/jenkins/gerrit-bazel-plugin-events-rabbitmq.yaml b/jenkins/gerrit-bazel-plugin-events-rabbitmq.yaml
index 455f39e..80ae280 100644
--- a/jenkins/gerrit-bazel-plugin-events-rabbitmq.yaml
+++ b/jenkins/gerrit-bazel-plugin-events-rabbitmq.yaml
@@ -4,4 +4,9 @@
       - 'plugin-{name}-bazel-{branch}':
           branch:
             - master
+      - 'plugin-{name}-bazel-{branch}-{gerrit-branch}':
+          branch:
+            - master
+          gerrit-branch:
+            - stable-3.7
       - 'plugin-{name}-verifier'