Pagure - reference pipelines add open: True requirement

Without this requirement it was possible to run jobs via
a recheck on closed pull requests. Recommended pipelines
should not allow that.

Change-Id: I9693d9ab906024137d48b4d473d1292a383d9e65

doc/source/admin/examples/pipelines/pagure-reference-pipelines.yaml

@@ -4,6 +4,7 @@
     require:
       pagure.io:
         merged: False
+        open: True
     trigger:
       pagure.io:
         - event: pg_pull_request
@@ -35,6 +36,7 @@
       pagure.io:
         score: 1
         merged: False
+        open: True
         tags: gateit
         status: success
       sqlreporter: