Fixed #9462 -- Set the instance in an inline formset correctly so that None...

Fixed #9462 -- Set the instance in an inline formset correctly so that None does not get passed through to the queryset. Thanks tobias and copelco for the ticket.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@9293 bcc190cf-cafb-0310-a4f2-bffc1f526a37