Stephen Shirley c725de7b5b Remove trailing , from CELERYBEAT_SCHEDULE example.
If a user copies the example verbatim, celery logs this error:
```
[2018-04-07 14:57:29,930: ERROR/MainProcess] Cannot add entry 'update_all_corpstats' to database schedule: TypeE rror('from_entry() argument after ** must be a mapping, not tuple',). Contents: ({'task': 'allianceauth.corputil s.tasks.update_all_corpstats', 'schedule': <crontab: 0 */6 * * * (m/h/d/dM/MY)>},)
```
2018-04-08 11:42:18 +02:00
..
2018-02-23 21:34:48 -05:00