This fixes invocation of any indexing lister without providing any bounds arguments to the run method.
For instance, you can start a full github listing in the docker environment trough the following command:

$ docker-compose exec swh-scheduler-api swh scheduler task add list-github-incremental -p oneshot

Related T2001

The test implemented for the Phabricator lister in D1982 has been moved to the HttpListerTester class
as it was written to check that case.