another try to filter master from CircleCI jobs (#2734)

* circleci config

* Apply suggestions from code review

* miss

.circleci/config.yml

@@ -153,11 +153,11 @@ workflows:
           filters:
             branches:
               # https://discuss.circleci.com/t/create-separate-steps-jobs-for-pr-forks-versus-branches/13419/4
-              only:
-                # only from forks
-                - /^pull\/.*$/
-                # only from canonical repository
-                - /^(?!pull\/).*$/
+              #only:
+              #  # only from forks
+              #  - /^pull\/.\d+$/
+              ignore:
+                - master
   cleanup:
     triggers:
       - schedule: