Removing unneeded from __future__ import statements.

Since we are on Python 3.6 and up, we don't need those anymore.

ebook_converter/utils/xml_parse.py

@@ -1,15 +1,9 @@
-#!/usr/bin/env python2
-# vim:fileencoding=utf-8
-# License: GPL v3 Copyright: 2019, Kovid Goyal <kovid at kovidgoyal.net>
-
-from __future__ import absolute_import, division, print_function, unicode_literals
-
 from lxml import etree
 
+
 # resolving of SYSTEM entities is turned off as entities can cause
 # reads of local files, for example:
 # <!DOCTYPE foo [ <!ENTITY passwd SYSTEM "file:///etc/passwd" >]>
-
 fs = etree.fromstring