Py3: Remove subclassing from object

Python 2 had old style and new style classes. Python 3 has only new
style classes. There is no point to subclass from object any more.

See: https://pagure.io/freeipa/issue/7715
Signed-off-by: Christian Heimes <cheimes@redhat.com>
Reviewed-By: Florence Blanc-Renaud <frenaud@redhat.com>

ipalib/config.py

@@ -53,7 +53,8 @@ from ipalib import errors
 if six.PY3:
     unicode = str
 
-class Env(object):
+
+class Env:
     """
     Store and retrieve environment variables.