Build audit-sl4j plugin on stable-3.4 branch

Change-Id: I95183dc04b6b124ffdbf8ddf73902c04cc3b9edb
diff --git a/jenkins/gerrit-bazel-plugin-audit-sl4j.yaml b/jenkins/gerrit-bazel-plugin-audit-sl4j.yaml
index bce7ced..448536a 100644
--- a/jenkins/gerrit-bazel-plugin-audit-sl4j.yaml
+++ b/jenkins/gerrit-bazel-plugin-audit-sl4j.yaml
@@ -8,3 +8,8 @@
             - stable-3.2
             - stable-3.1
             - stable-2.16
+      - 'plugin-{name}-bazel-{branch}-{gerrit-branch}':
+          branch:
+            - master
+          gerrit-branch:
+            - stable-3.4