outbound thread crash

[PeterSurda]

Traceback (most recent call last):
  File "/usr/lib/python2.7/threading.py", line 810, in __bootstrap_inner
    self.run()
  File "/usr/lib/python2.7/threading.py", line 763, in run
    self.__target(*self.__args, **self.__kwargs)
  File "/opt/bitmessage-email-gateway/bitmessage-gateway.py", line 633, in check_bmoutbox
    if a_message['status'] == 'ackreceived':
KeyError: 'status'