bug/ _wait_until_wake_word bad return type

[JarbasAl]

reported by @j1nx

2022-02-09 19:58:47.774 - OVOS - mycroft.client.speech.listener:run:396 - DEBUG - Config has changed, reloading...
2022-02-09 19:58:47.817 - OVOS - mycroft.client.speech.listener:run:97 - ERROR - Exception in AudioProducer
Traceback (most recent call last):
  File "/usr/lib/python3.8/site-packages/mycroft/client/speech/listener.py", line 72, in run
    audio, lang = self.loop.responsive_recognizer.listen(
  File "/usr/lib/python3.8/site-packages/mycroft/client/speech/mic.py", line 802, in listen
    ww_data, lang = self._wait_until_wake_word(source, sec_per_buffer)
TypeError: cannot unpack non-iterable NoneType object

[j1nx]

Additional info, this only happened at first boot. On second boot (reboot) the config has changed, reloading did not happen and the error after that was not logged.