[1.0.X] Fixed #9863. A ForeignKey with editable=False to the parent in an...

[1.0.X] Fixed #9863. A ForeignKey with editable=False to the parent in an inline no longer raises an exception. Thanks to keithb for the test case and Alex Gaynor for the patch. Backport of r10239 from trunk.


git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.0.X@10287 bcc190cf-cafb-0310-a4f2-bffc1f526a37