net/iodine: make port configurable

Fall back to the default DNS port (i.e. 53). If you configure something
different than 53 this results in a warning from iodined:

	ALERT! Other dns servers expect you to run on port 53.
	You must manually forward port 53 to port $port for things to work.

This is obviously true.

Signed-off-by: Uwe Kleine-König <uwe+openwrt@kleine-koenig.org>

net/iodine/files/iodined.init

@@ -9,8 +9,11 @@ start_instance () {
 	config_get password "$section" 'password'
 	config_get tunnelip "$section" 'tunnelip'
 	config_get tld      "$section" 'tld'
+	config_get port     "$section" 'port'
 	
-	service_start /usr/sbin/iodined -l "$address" -P "$password" "$tunnelip" "$tld"
+	test -n "$port" || port='53'
+
+	service_start /usr/sbin/iodined -l "$address" -P "$password" -p "$port" "$tunnelip" "$tld"
 }
 
 start() {