Due to a wrong understanding of how the Translation Platform integration
scripts work, we have previously configured force-pushes from the
integration repo into the new gatekeeper repository.

Actually, such forcing shouldn't be necessary because:

  - Gatekeeper should always be a subset of GitLab, and
  - Integration should fail early when fast-forwarding is not possible.

This commit only reverts the pushing from integration to gatekeeper to
be a normal push instead of a force-push.