Restore instance context when getting price list used

The price_list_used is set on property so it is executed under the transaction
context but we expect to have the price list from the company set in the
instance context.

issue10664
review369491002

product.py

@@ -589,7 +589,10 @@ class Product(
 
     @property
     def list_price_used(self):
-        return self.template.get_multivalue('list_price')
+        transaction = Transaction()
+        with transaction.reset_context(), \
+                transaction.set_context(self._context):
+            return self.template.get_multivalue('list_price')
 
     @classmethod
     def sync_code(cls, products):