Clarify docs on the change from redirect_enabled.

(cherry picked from commit eebdabb)

doc/admin-guide/files/records.config.en.rst

@@ -1332,6 +1332,8 @@ HTTP Redirection
 
    .. note:: When :ts:cv:`proxy.config.http.number_of_redirections` is set to a positive value and |TS| has previously cached a 3XX Redirect response, the cached response will continue to be refreshed and returned until the response is no longer in the cache.
 
+   .. note:: In previous versions proxy.config.http.redirection_enabled had to be set to 1 before this setting was evaluated.  Now setting :ts:cv:`proxy.config.http.number_of_redirections` to a value greater than zero is sufficient to cause |TS| to follow redirects.
+
 .. ts:cv:: CONFIG proxy.config.http.redirect_host_no_port INT 1
    :reloadable: