Lack of configured consumers raises exception

[gmr]

TypeError: 'NoneType' object is not iterable
  File "bin/rejected", line 11, in <module>
    sys.exit(main())
  File "rejected/controller.py", line 150, in main
    helper.start(Controller)
  File "helper/__init__.py", line 174, in start
    obj.start()
  File "helper/controller.py", line 266, in start
    self.run()
  File "rejected/controller.py", line 100, in run
    self._mcp = self._master_control_program()
  File "rejected/controller.py", line 51, in _master_control_program
    quantity=self.args.quantity)
  File "rejected/mcp.py", line 65, in __init__
    self.consumer_cfg = self.get_consumer_cfg(config, consumer, quantity)
  File "rejected/mcp.py", line 249, in get_consumer_cfg
    consumers = dict(config.application.Consumers)

[gmr]

https://sentry.io/aweber-communications/rejected/issues/471569471/