Fixed import typos in the docs.

docs/ref/request-response.txt

@@ -252,7 +252,7 @@ Methods
         behind multiple proxies. One solution is to use middleware to rewrite
         the proxy headers, as in the following example::
 
-            from django.django.utils.deprecation import MiddlewareMixin
+            from django.utils.deprecation import MiddlewareMixin
 
             class MultipleProxyMiddleware(MiddlewareMixin):
                 FORWARDED_FOR_FIELDS = [

docs/topics/i18n/timezones.txt

@@ -178,7 +178,7 @@ Add the following middleware to :setting:`MIDDLEWARE`::
     import pytz
 
     from django.utils import timezone
-    from django.django.utils.deprecation import MiddlewareMixin
+    from django.utils.deprecation import MiddlewareMixin
 
     class TimezoneMiddleware(MiddlewareMixin):
         def process_request(self, request):