Update backup.py

# -*- encoding: utf-8 -*-
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#
#    OpenERP, Open Source Enterprise Resource Planning and Management Solution
#
#    Copyright (c) 2013 ITpedia Solutions LLC. All Rights Reserved
#    Author: Mohammed Arif <arif.marias@itpedia-soltutions.com>
#
#    Copyright (C) 2010 Gábor Dukai <gdukai@gmail.com>
#    
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation, either version 3 of the License, or
#    (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
##############################################################################