- fix coding declaration

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@26819 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/Document/TradeModelRule.py

-# -*- coding: utf8 -*-
+# -*- coding: utf-8 -*-
 ##############################################################################
 #
 # Copyright (c) 2009 Nexedi SARL and Contributors. All Rights Reserved.