Merge branch 'mj/review-apps-guard' into 'master'

Review apps cleanup schedule runs on master

See merge request gitlab-org/gitlab-ce!22601

.gitlab-ci.yml

@@ -1011,6 +1011,5 @@ schedule:review_apps_cleanup:
       - schedules@gitlab-org/gitlab-ee
     kubernetes: active
   except:
-    - master
     - tags
     - /(^docs[\/-].*|.*-docs$)/