dialplan: docs - note about limiting to max 1 rpc reload in 5 seconds

(cherry picked from commit 34f928427ecf315f638cd59fa512d59f4c64f22e)
(cherry picked from commit e1116aca38ad55305593c8936fcacff0d00cf668)
(cherry picked from commit 4a8a1e858afb2ea88442d7fa82ea38b2df47c532)

src/modules/dialplan/doc/dialplan_admin.xml

@@ -501,7 +501,8 @@ xlog("translated to var $var(y) \n");
 		<function moreinfo="none">dp_reload()</function>
 		</title>
 		<para>
-		Forces an update of the translation rules from the database.
+		Reload the translation rules from the database. Note that there is
+		a rate limiting of maximum one reload in five seconds.
 		</para>
 		<para>
 		Name: <emphasis>dp_reload</emphasis>