[FIX] wesbite_sale: recompute taxes when fiscal position is updated

We force to recompute the taxes on all lines when we change the fiscal position.
That was already done in backend, with the onchange.
But @api.contrains allow to do it on each write on fiscal_position_id field.

@api.Depends will not work because it is not a computed field.

addons/sale/sale.py

@@ -85,6 +85,7 @@ class SaleOrder(models.Model):
         default_team_id = self.env['crm.team']._get_default_team_id()
         return self.env['crm.team'].browse(default_team_id)
 
+    @api.constrains('fiscal_position_id')
     @api.onchange('fiscal_position_id')
     def _compute_tax_id(self):
         """

addons/website_sale/controllers/main.py

@@ -625,7 +625,6 @@ class website_sale(http.Controller):
             partner_id = orm_partner.create(cr, SUPERUSER_ID, billing_info, context=context)
         order.write({'partner_id': partner_id, 'partner_invoice_id': partner_id})
         order_obj.onchange_partner_id(cr, SUPERUSER_ID, [order.id], context=context)
-        order_obj.onchange_partner_shipping_id(cr, SUPERUSER_ID, [order.id], context=context)
 
         # create a new shipping partner
         if checkout.get('shipping_id') == -1:
@@ -635,7 +634,8 @@ class website_sale(http.Controller):
             shipping_info['parent_id'] = partner_id
             checkout['shipping_id'] = orm_partner.create(cr, SUPERUSER_ID, shipping_info, context)
             order.write({'partner_shipping_id': checkout.get('shipping_id')})
-            order_obj.onchange_partner_shipping_id(cr, SUPERUSER_ID, [order.id], context=context)
+
+        order_obj.onchange_partner_shipping_id(cr, SUPERUSER_ID, [order.id], context=context)
 
         order_info = {
             'message_partner_ids': [(4, partner_id), (3, request.website.partner_id.id)],