Fixed #10893 -- Corrected a problem with using list_editable in the admin when...

Fixed #10893 -- Corrected a problem with using list_editable in the admin when the model has a manual primary key. Thanks to Alex Gaynor for the patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@10681 bcc190cf-cafb-0310-a4f2-bffc1f526a37