[basetemplate] Remove misleading comment
The <base> tag was removed in commit 8bf2337a6f3b back in 2011.
# -*- 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"""