Build lfs plugin on stable-3.4 branch

Change-Id: I1762eb69ae9d9f9f4004cbbca209571c2b634223
diff --git a/jenkins/gerrit-bazel-plugin-lfs.yaml b/jenkins/gerrit-bazel-plugin-lfs.yaml
index b67e4a8..9676065 100644
--- a/jenkins/gerrit-bazel-plugin-lfs.yaml
+++ b/jenkins/gerrit-bazel-plugin-lfs.yaml
@@ -6,6 +6,7 @@
             - master
           gerrit-branch:
             - master
+            - stable-3.4
             - stable-3.3
             - stable-3.2
       - 'plugin-{name}-bazel-{branch}':