Build github plugin on stable-3.5 branch

Change-Id: I7914c323840598a90619359a9262772073eeec9b
diff --git a/jenkins/gerrit-mvn-plugin-github.yaml b/jenkins/gerrit-mvn-plugin-github.yaml
index 3d58ff5..f6b79d6 100644
--- a/jenkins/gerrit-mvn-plugin-github.yaml
+++ b/jenkins/gerrit-mvn-plugin-github.yaml
@@ -3,6 +3,7 @@
     repo: github
     branch:
       - master
+      - stable-3.5
       - stable-3.4
       - stable-3.3
       - stable-3.2