Fix OpenTTD#12301: Update v->dest_tile when relocating buoys

Moving buoys caused current_order to be detected as unchanged, making pathfinders to compute a path to an outdated v->dest_tile.

Properly update v->dest_tile before reaching pathfinders.

src/order_cmd.cpp

@@ -2197,8 +2197,9 @@ bool ProcessOrders(Vehicle *v)
 	}
 
 	/* If it is unchanged, keep it. */
-	if (order->Equals(v->current_order) && (v->type == VEH_AIRCRAFT || v->dest_tile != 0) &&
-			(v->type != VEH_SHIP || !order->IsType(OT_GOTO_STATION) || Station::Get(order->GetDestination())->ship_station.tile != INVALID_TILE)) {
+	if (order->Equals(v->current_order) && (v->type == VEH_AIRCRAFT || v->dest_tile != 0) && (v->type != VEH_SHIP ||
+			((!order->IsType(OT_GOTO_STATION) || Station::Get(order->GetDestination())->ship_station.tile != INVALID_TILE) &&
+			(!order->IsType(OT_GOTO_WAYPOINT) || Waypoint::Get(order->GetDestination())->xy == v->dest_tile)))) {
 		return false;
 	}