[FIX] point_of_sale: wrong empty attribute

`currentOrder` does not exist in the `Product` model

closes odoo/odoo#114768

Signed-off-by: Samuel Degueldre <sad@odoo.com>

addons/point_of_sale/static/src/js/models.js

@@ -1521,7 +1521,7 @@ export class Product extends PosModel {
             if (isAllowOnlyOneLot) {
                 packLotLinesToEdit = [];
             } else {
-                const orderline = this.currentOrder
+                const orderline = this.pos.selectedOrder
                     .get_orderlines()
                     .filter((line) => !line.get_discount())
                     .find((line) => line.product.id === this.id);