Fixed #10953, #10955: proxies of proxies now work correctly, though I still...

Fixed #10953, #10955: proxies of proxies now work correctly, though I still don't quite understand why you'd want to do such a thing. Thanks, Armin Ronacher.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@10738 bcc190cf-cafb-0310-a4f2-bffc1f526a37