declare used encoding on python file. This is mandatory! Allows file to be imported on Python 2.6

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@30825 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/tests/testERP5Commerce.py

+# encoding: utf-8
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