Fixed #10448: correcting errors on "save as new" now correctly create a new...

Fixed #10448: correcting errors on "save as new" now correctly create a new object instead of modifying the old one. Thanks, bastih.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@10713 bcc190cf-cafb-0310-a4f2-bffc1f526a37