Do not copy asset lot when copying sale subscription line

Closes #13785

modules/sale_subscription_asset/sale.py

@@ -117,5 +117,5 @@ class SubscriptionLine(metaclass=PoolMeta):
             default = {}
         else:
             default = default.copy()
-        default.setdefault('lot')
+        default.setdefault('asset_lot')
         return super(SubscriptionLine, cls).copy(lines, default)