Fixed #13030 -- Corrected natural key deserialization to subclasses. Thanks to...

Fixed #13030 -- Corrected natural key deserialization to subclasses. Thanks to yishaibeeri for the report and test case.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@12804 bcc190cf-cafb-0310-a4f2-bffc1f526a37