Fixed #13336 -- Corrected an incorrect example of cache header usage.…

… Thanks to dnjuls for the report, and claudep for the patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@13129 bcc190cf-cafb-0310-a4f2-bffc1f526a37

docs/ref/request-response.txt

@@ -434,7 +434,7 @@ Setting headers
 To set a header in your response, just treat it like a dictionary::
 
     >>> response = HttpResponse()
-    >>> response['Pragma'] = 'no-cache'
+    >>> response['Cache-Control'] = 'no-cache'
 
 .. versionadded:: 1.1