uo4: add postmerge job to project

Change-Id: I520066b57b2c5ac666a348242d42b559e9724965
diff --git a/jjb/verify/up4.yaml b/jjb/verify/up4.yaml
index 3c3327f..17788a6 100644
--- a/jjb/verify/up4.yaml
+++ b/jjb/verify/up4.yaml
@@ -19,6 +19,7 @@
     name: "up4-jobs"
     jobs:
       - "up4-pr-verify"
+      - "up4-postmerge"
 
 - job-template:
     id: "up4-pr-verify"