Documenting kinit_lifetime in /etc/ipa/default.conf

Describing the parameter kinit_lifetime that allows to limit the lifetime of ticket obtained by users authenticating to the WebGUI using login/password. Removing session_auth_duration and session_duration_type since these parameters are not relevant anymore.

Resolves: https://pagure.io/freeipa/issue/7333
Reviewed-By: Florence Blanc-Renaud <flo@redhat.com>

pylint_plugins.py

@@ -67,8 +67,6 @@ NAMESPACE_ATTRS = ['Command', 'Object', 'Method', fake_backend, 'Updater',
 fake_api_env = {'env': [
     'host',
     'realm',
-    'session_auth_duration',
-    'session_duration_type',
     'kinit_lifetime',
 ]}