Build multi-site on stable-3.1

Change-Id: Id763eb5c9e889a4d6a064e0e50a59097f6fc0e8a
diff --git a/jenkins/gerrit-bazel-plugin-multi-site.yaml b/jenkins/gerrit-bazel-plugin-multi-site.yaml
index 6d2d001..66d99ef 100644
--- a/jenkins/gerrit-bazel-plugin-multi-site.yaml
+++ b/jenkins/gerrit-bazel-plugin-multi-site.yaml
@@ -1,13 +1,9 @@
 - project:
     name: multi-site
     jobs:
-      - 'plugin-{name}-bazel-{branch}-{gerrit-branch}':
-          branch:
-            - master
-          gerrit-branch:
-            - master
-            - stable-3.1
       - 'plugin-{name}-bazel-{branch}':
           branch:
+            - master
+            - stable-3.1
             - stable-3.0
             - stable-2.16