Fixed #9494 -- Ensure the foreign key in an inline formset is always present...

Fixed #9494 -- Ensure the foreign key in an inline formset is always present on the forms. Thanks Fugazi for the report.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@9326 bcc190cf-cafb-0310-a4f2-bffc1f526a37