[FIX] product: compute product variant names using attribute sequences

Commit: 70e1efd41e
Explicitly added an _order on product.attribute.value.
However the order that should be used first is the one from product.attribute.
It would not make sense to display ipod (white, 8go) and ipod (8go, black).

opw 1883904

addons/product/models/product_attribute.py

@@ -21,7 +21,7 @@ class ProductAttribute(models.Model):
 
 class ProductAttributevalue(models.Model):
     _name = "product.attribute.value"
-    _order = 'sequence, attribute_id, id'
+    _order = 'attribute_id, sequence, id'
 
     name = fields.Char('Attribute Value', required=True, translate=True)
     sequence = fields.Integer('Sequence', help="Determine the display order")