Exit with nice error message failing to get repositories

If we throw an OfflineImapError in case of the Repository()
initialization, we display the nice error message and exit rather
than bomb out with a traceback. Misconfiguring a repository name in
the configuration file is now nicely pointed out to the user.

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

offlineimap/accounts.py

@@ -217,6 +217,7 @@ class SyncableAccount(Account):
 
     def syncrunner(self):
         self.ui.registerthread(self)
+        try:
             accountmetadata = self.getaccountmeta()
             if not os.path.exists(accountmetadata):
                 os.mkdir(accountmetadata, 0o700)
@@ -224,6 +225,11 @@ class SyncableAccount(Account):
             self.remoterepos = Repository(self, 'remote')
             self.localrepos  = Repository(self, 'local')
             self.statusrepos = Repository(self, 'status')
+        except OfflineImapError as e:
+            self.ui.error(e, exc_info()[2])
+            if e.severity >= OfflineImapError.ERROR.CRITICAL:
+                raise
+            return
 
         # Loop account sync if needed (bail out after 3 failures)
         looping = 3