Change OpenTTD#6493: Only serviceathelipad when breakdowns are enable…

…d or when no_servicing_if_no_breakdowns is disabled

Helicopters with 'service at helipads' enabled, will only do so when 'disable servicing when servicing set to none' is disabled, or, if enabled, when 'vehicle breakdowns' is not set to none.

src/aircraft_cmd.cpp

@@ -1542,7 +1542,8 @@ static void AircraftEventHandler_AtTerminal(Aircraft *v, const AirportFTAClass *
 		AircraftEventHandler_EnterTerminal(v, apc);
 		/* on an airport with helipads, a helicopter will always land there
 		 * and get serviced at the same time - setting */
-		if (_settings_game.order.serviceathelipad) {
+		if ((!_settings_game.order.no_servicing_if_no_breakdowns || _settings_game.difficulty.vehicle_breakdowns != 0) &&
+				_settings_game.order.serviceathelipad) {
 			if (v->subtype == AIR_HELICOPTER && apc->num_helipads > 0) {
 				/* an excerpt of ServiceAircraft, without the invisibility stuff */
 				v->date_of_last_service = _date;