Fixed #12692 - Properly handle the extra clause of admin inline formsets. Also...

Fixed #12692 - Properly handle the extra clause of admin inline formsets. Also fixes #12703, second error.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@12369 bcc190cf-cafb-0310-a4f2-bffc1f526a37