Fixed #8997 -- Prevented the contenttypes `shortcut` view to hide errors...

Fixed #8997 -- Prevented the contenttypes `shortcut` view to hide errors occurring inside the `get_absolute_url()` method. Thanks to Rob for the report and to joshlory, Aymeric Augustin and Claude Paroz for the patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@17328 bcc190cf-cafb-0310-a4f2-bffc1f526a37