Ignore the error if product not there

As we are changing the list of products

api/db/order.go

@@ -118,10 +118,7 @@ func (d *DB) UpdateOrder(memberNum int, id int, order *Order) error {
 			if err != nil {
 				return err
 			}
-			total, err := calculateOrderPurchaseTotal(transaction.OrderPurchase, order.Products)
-			if err != nil {
-				return err
-			}
+			total, _ := calculateOrderPurchaseTotal(transaction.OrderPurchase, order.Products)
 			err = updateOrderPurchase(tx, t.MemberNum, &dbOrder.Transactions[i], total, t.OrderPurchase)
 			if err != nil {
 				return err