Add stable-2.12 to quota

Change-Id: I1fec4e819f3e526a41c7e1b0d22a8d5066d88de5
diff --git a/jenkins/gerrit-buck-plugin-quota.yaml b/jenkins/gerrit-buck-plugin-quota.yaml
index 94b8fad..eeb15b1 100644
--- a/jenkins/gerrit-buck-plugin-quota.yaml
+++ b/jenkins/gerrit-buck-plugin-quota.yaml
@@ -2,6 +2,7 @@
     name: quota
     branch:
       - master
+      - stable-2.12
       - stable-2.11
     jobs:
       - 'plugin-{name}-{branch}'