Rename GitLabListerTask in _GitLabListerTaskBase
since
1/ it's a 'private' class (no reason to use it from any other place than this module), and
2/ it's an 'abstract' base class
This is needed (at least one of the 2 parts of the rename, but both make sense semantically for the reasons listed above) to make it compatible with the new auto register mechanism introduced in swh-scheduler 0.0.38; note however that this requires swh-scheduler!28 (closed) to behave properly.
Migrated from D869 (view on Phabricator)