Fixed #17316 -- Mentionned that the MultipleProxyMiddleware provided as an example must run rather early.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@17556 bcc190cf-cafb-0310-a4f2-bffc1f526a37

docs/ref/request-response.txt

@@ -228,6 +228,10 @@ Methods
                                 parts = request.META[field].split(',')
                                 request.META[field] = parts[-1].strip()
 
+        This middleware should be positionned before any other middleware that
+        relies on the value of :meth:`~HttpRequest.get_host()`, for instance
+        :class:`~django.middleware.common.CommonMiddleware` or
+        :class:`~django.middleware.csrf.CsrfViewMiddleware`.
 
 .. method:: HttpRequest.get_full_path()