[Buildbot] #3182: MailNotifier throws exceptions.AttributeError: 'NoneType' object has no attribute 'subscribe'

[Buildbot trac]

#3182: MailNotifier throws exceptions.AttributeError: 'NoneType' object has no
attribute 'subscribe'
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Reporter:  daniel@…   |       Owner:
    Type:  undecided  |      Status:  new
Priority:  major      |   Milestone:  undecided
 Version:  master     |  Resolution:
Keywords:  mail, osx  |
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Comment (by ewong):

 the fix was easy to figure out.  Now I need to figure out the test that
 needs to come with it.

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Ticket URL: <http://trac.buildbot.net/ticket/3182#comment:4>
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