Fixed a typo in the time zone docs. Thanks Ramiro.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@17646 bcc190cf-cafb-0310-a4f2-bffc1f526a37

docs/topics/i18n/timezones.txt

@@ -685,7 +685,7 @@ Usage
    the datetime in UTC returned by :func:`django.utils.timezone.now` will be
    sufficient.
 
-   For the shake of completeness, if you really wanted the current time in the
+   For the sake of completeness, if you really wanted the current time in the
    local time zone, here's how you would obtain it::
 
        >>> import datetime