Fixed #15083 -- Corrected the order of TemplateResponse middleware handling, ensuring that custom URLConfs are valid, and that ResponseMiddleware is invoked if the TemplateResponseMiddleware causes errors. Thanks to Sayane for the report.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@15226 bcc190cf-cafb-0310-a4f2-bffc1f526a37