Build analytics for v2.14, v2.15 and master

Use different branches for the analytics plugin
for targeting Gerrit v2.14, v2.15 and master.

Change-Id: I38841e3595bc3192b8d8479d821de530d092b779
diff --git a/jenkins/gerrit-sbt-plugin-analytics.yaml b/jenkins/gerrit-sbt-plugin-analytics.yaml
index 3f85b02..685c4c0 100644
--- a/jenkins/gerrit-sbt-plugin-analytics.yaml
+++ b/jenkins/gerrit-sbt-plugin-analytics.yaml
@@ -1,11 +1,8 @@
 - project:
     name: analytics
     jobs:
-      - 'plugin-{name}-sbt-{branch}-{gerrit-branch}':
+      - 'plugin-{name}-sbt-{branch}':
           branch:
             - master
-          gerrit-branch:
-            - master
             - stable-2.15
             - stable-2.14
-            - stable-2.13