Another stack trace

[John Wiegley]

Some more cases where None isn't considered:

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Syncing [Gmail]/Trash: IMAP -> MappedIMAP
ERROR [<InstanceLimitedThread(Folder sync [Gmail], started daemon 4466937856)>]: ERROR in syncfolder for Gmail folder [Gmail]/Trash: Traceback (most recent call last):
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/offlineimap/accounts.py", line 388, in syncfolder
    remotefolder.cachemessagelist()
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/offlineimap/folder/IMAP.py", line 179, in cachemessagelist
    messagestr = messagestr.split(' ', 1)[1]
AttributeError: 'NoneType' object has no attribute 'split'

  'NoneType' object has no attribute 'split'
--8<---------------cut here---------------end--------------->8---

John