Fixed #12851 -- Corrected the loading of values when select_related() is used...

Fixed #12851 -- Corrected the loading of values when select_related() is used on inherited models. Thanks to phxx for the report and test case.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@13054 bcc190cf-cafb-0310-a4f2-bffc1f526a37