[1.2.X] Fixed #13661 -- Corrected example in the serialization docs. …

…Thanks to jabapyth for the report.

Backport of r13530 from trunk.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.2.X@13536 bcc190cf-cafb-0310-a4f2-bffc1f526a37

docs/topics/serialization.txt

@@ -338,7 +338,7 @@ example, ``(first name, last name)``. Then, when you call
 ``serializers.serialize()``, you provide a ``use_natural_keys=True``
 argument::
 
-    >>> serializers.serialize([book1, book2], format='json', indent=2, use_natural_keys=True)
+    >>> serializers.serialize('json', [book1, book2], indent=2, use_natural_keys=True)
 
 When ``use_natural_keys=True`` is specified, Django will use the
 ``natural_key()`` method to serialize any reference to objects of the