Fixed #14068 -- Corrected error handling in loaddata when an allow_syncdb...

Fixed #14068 -- Corrected error handling in loaddata when an allow_syncdb method is defined on the router. Thanks to Xavier Ordoquy for the report.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@13612 bcc190cf-cafb-0310-a4f2-bffc1f526a37