[FIX] sale_product_configurator: edit product with variants sale line

Issue:
======
When you edit an already saved product line which has variants it will
throw an error.

Steps to reproduce the error:
=============================
1-create 2 products having at least one variant each and make them
storable
2-create a sale order and add only the first product and save the SO
3-edit the sale line of the first product with the second product and
try to save it

Origin of the problem:
======================
When retrieving combination we didn't check that the variants are
associated to the product.

Solution:
=========
Try to get the variants that are associated to the product , if there is
no such variants we apply get_first_possible_combination

opw-3423065
opw-3450266

closes odoo/odoo#132527

X-original-commit: 06d18005762377c5188c5537ba4d17c4efd66948
Signed-off-by: Mahdi Cheikh Rouhou (macr) <macr@odoo.com>

addons/sale_product_configurator/controllers/main.py

@@ -42,9 +42,10 @@ class ProductConfiguratorController(Controller):
             request.update_context(allowed_company_ids=[company_id])
         product_template = request.env['product.template'].browse(product_template_id)
 
+        combination = request.env['product.template.attribute.value']
         if ptav_ids:
-            combination = request.env['product.template.attribute.value'].browse(ptav_ids)
-        else:
+            combination = request.env['product.template.attribute.value'].browse(ptav_ids).filtered(lambda ptav: ptav.product_tmpl_id.id == product_template_id)
+        if not combination:
             combination = product_template._get_first_possible_combination()
 
         return dict(