[FIX] website_sale_delivery: round delivery price

`delivery_price` is a float, therefore we round it to the currency since
a carrier could send more than the expected number of decimals.

opw-804374

addons/website_sale_delivery/controllers/main.py

@@ -65,7 +65,7 @@ class WebsiteSaleDelivery(WebsiteSale):
             return {'status': order.delivery_rating_success,
                     'error_message': order.delivery_message,
                     'carrier_id': carrier_id,
-                    'new_amount_delivery': order.delivery_price,
+                    'new_amount_delivery': order.currency_id.round(order.delivery_price),
                     'new_amount_untaxed': order.amount_untaxed,
                     'new_amount_tax': order.amount_tax,
                     'new_amount_total': order.amount_total,