Stop doing catalog backups

Stop doing catalog backups

The bacula catalog backup job is this special snowflake that's unlike
all the other jobs.  It only backups one file,
/var/lib/bacula/bacula.sql.gz, that gets created in a RunBeforeJob
and deleted in a RunAfterJob.

We already have a well-thought out and more generic method to backup
databases, and we should use just that.

The RunBefore/After setup makes sense as a default when you don't have
that, but we do.