Fixed #13026 - Also update the index of lookup links when adding inlines...

Fixed #13026 - Also update the index of lookup links when adding inlines dynmacially in the admin. Thanks to ramusus and Rob Hudson for the patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@12784 bcc190cf-cafb-0310-a4f2-bffc1f526a37