Merge pull request #1289 from closeio/fix-typo

Fix typo in the docstring for __len__

mongoengine/queryset/queryset.py

@@ -38,7 +38,7 @@ class QuerySet(BaseQuerySet):
 
     def __len__(self):
         """Since __len__ is called quite frequently (for example, as part of
-        list(qs) we populate the result cache and cache the length.
+        list(qs)), we populate the result cache and cache the length.
         """
         if self._len is not None:
             return self._len