Fix the default sorting for jobs

The UI would indicate a default sort by title when visiting the jobs
page.  This sort did not actually work, though, because sort was only
applied when an explicit order_by argument was given on the url.
I'd rephrase here, `Unknown order key %r.  Options are 'title', 'state', 'time_submitted', 't_queued', 't_running', 't_failed' or 't_done'`