[dataimport] Format strings with % instead of .format()
For consistency with CubicWeb code base and to avoid Python 2.6
compatibility traps.
# -*- coding: utf-8 -*-
# copyright %(year)s %(author)s, all rights reserved.
# contact %(author-web-site)s -- mailto:%(author-email)s
#
%(long-license)s
"""%(distname)s specific hooks and operations"""