Prevent scheduler job duplication (ValueError: There's already an active RQ scheduler)
After server re-deploy for a few mins the scheduler doesn't know the old scheduler has gone away.
Also look into clearing scheduler queue on app boot, otherwise scheduler jobs will double up. http://stackoverflow.com/a/32033454/1345360
ValueError: There's already an active RQ scheduler File "django_rq/management/commands/rqscheduler.py", line 35, in handle scheduler.run()