Scheduled Dispatch: Fix bug resulting in a hang

If a vechile order is decloned.

src/order_cmd.cpp

@@ -1132,6 +1132,11 @@ void InsertOrder(Vehicle *v, Order *new_o, VehicleOrderID sel_ord)
 static CommandCost DecloneOrder(Vehicle *dst, DoCommandFlag flags)
 {
 	if (flags & DC_EXEC) {
+		/* Clear cheduled dispatch flag if any */
+		if (HasBit(dst->vehicle_flags, VF_SCHEDULED_DISPATCH)) {
+			ClrBit(dst->vehicle_flags, VF_SCHEDULED_DISPATCH);
+		}
+
 		DeleteVehicleOrders(dst);
 		InvalidateVehicleOrder(dst, VIWD_REMOVE_ALL_ORDERS);
 		InvalidateWindowClassesData(GetWindowClassForVehicleType(dst->type), 0);