init.py: Import OfflineImapError

The next commit will make use of OfflineImapError but is transient (the
old-style lock). The commit is supposed to be reverted after a few
releases. So add the new import in a separate commit, because we might
need this even when reverting the commit.

Signed-off-by: Sebastian Spaeth <Sebastian@SSpaeth.de>

offlineimap/init.py

@@ -26,6 +26,7 @@ import logging
 from optparse import OptionParser
 import offlineimap
 from offlineimap import accounts, threadutil, syncmaster
+from offlineimap.error import OfflineImapError
 from offlineimap.ui import UI_LIST, setglobalui, getglobalui
 from offlineimap.CustomConfig import CustomConfigParser