title: Celery beat doesn't run periodic task
body: <p>I have task</p>
  
  <pre><code>class BasecrmSync(PeriodicTask):
  run_every = schedules.crontab(minute='*/1')
  
  def run(self, **kwargs):
      bc = basecrm.Client(access_token=settings.BASECRM_AUTH_TOKEN)
      sync = basecrm.Sync(client=bc, device_uuid=settings.BASECRM_DEVICE_UUID)
      sync.fetch(synchronize)
  </code></pre>
  
  <p>And celery config with db broker</p>
  
  <pre><code>CELERY_RESULT_BACKEND='djcelery.backends.database:DatabaseBackend'
  BROKER_URL = 'django://'
  CELERYBEAT_SCHEDULER = 'djcelery.schedulers.DatabaseScheduler'
  </code></pre>
  
  <p>I run </p>
  
  <pre><code>celery -A renuval_api worker -B --loglevel=debug
  </code></pre>
  
  <p>But it doesn't run task...
  Also I've tried run by </p>
  
  <pre><code>python3 manage.py celery worker --loglevel=DEBUG  -E -B -c 1 --settings=renuval_api.settings.local
  </code></pre>
  
  <p>But It uses amqp transport and I can't understand why.</p>