fix-ci: backed out changeset 308e45f7b455

The  chg variant of the CI see a failure on `tests/test-narrow-pull.t`.
Bisecting point the failure as starting at this small changeset…

Backing it out, restore the CI on default. It was never broken on
stable, which is even more puzzling.
11 jobs for topic/default/fix-chg-failure in 28 minutes and 44 seconds (queued for 5 seconds)