Fixed Oracle backend failure in test suite for modeltests.queries. ...

Fixed Oracle backend failure in test suite for modeltests.queries.  Item.objects.all()[0:0] was optimizing out the limits clause and returning all rows.


git-svn-id: http://code.djangoproject.com/svn/django/trunk@8069 bcc190cf-cafb-0310-a4f2-bffc1f526a37