Build code-owners plugin on its own stable-3.4 branch

Change-Id: I3f5b1536f8af872f3b2d94b23e0c4dab9a97e2fa
diff --git a/jenkins/gerrit-bazel-plugin-code-owners.yaml b/jenkins/gerrit-bazel-plugin-code-owners.yaml
index 28fb3a3..14834df 100644
--- a/jenkins/gerrit-bazel-plugin-code-owners.yaml
+++ b/jenkins/gerrit-bazel-plugin-code-owners.yaml
@@ -4,9 +4,5 @@
       - 'plugin-{name}-bazel-{branch}':
           branch:
             - master
-            - stable-3.3
-      - 'plugin-{name}-bazel-{branch}-{gerrit-branch}':
-          branch:
-            - master
-          gerrit-branch:
             - stable-3.4
+            - stable-3.3