Support branches for extraConfigRepo
We simply need to make https://gitlab.cern.ch/drupal/paas/drupalsite-operator/blob/e80933fdc3a2684feefa94b94bbab532343c9b80/controllers/drupalsite_resources.go#L833 configurable.
We simply need to make https://gitlab.cern.ch/drupal/paas/drupalsite-operator/blob/e80933fdc3a2684feefa94b94bbab532343c9b80/controllers/drupalsite_resources.go#L833 configurable.