Build high-availability plugin on stable-3.0/master

Make sure that the high-availability plugin is built
on its own branch against the corresponding branch
of Gerrit, removing the cross-compile of master with stable-3.0.

Change-Id: I34469bd2f0841461425ba1ba1632925ff8d65d76
diff --git a/jenkins/gerrit-bazel-plugin-high-availability.yaml b/jenkins/gerrit-bazel-plugin-high-availability.yaml
index 169458e..144d91d 100644
--- a/jenkins/gerrit-bazel-plugin-high-availability.yaml
+++ b/jenkins/gerrit-bazel-plugin-high-availability.yaml
@@ -3,18 +3,15 @@
     jobs:
       - 'plugin-{name}-bazel-{branch}':
           branch:
+            - master
+            - stable-3.0
             - stable-2.16
             - stable-2.15
             - stable-2.14
-      - 'plugin-{name}-bazel-{branch}-{gerrit-branch}':
-          branch:
-            - master
-          gerrit-branch:
-            - master
-            - stable-3.0
       - 'plugin-{name}-gerritforge-{branch}':
           branch:
             - master
+            - stable-3.0
             - stable-2.16
             - stable-2.15
             - stable-2.14