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>

install/ui/test/data/ipa_init.json

@@ -920,7 +920,6 @@
                "container_sysaccounts" : "cn=sysaccounts,cn=etc",
                "dogtag_version" : 10,
                "container_rolegroup" : "cn=roles,cn=accounts",
-               "session_duration_type" : "inactivity_timeout",
                "container_s4u2proxy" : "cn=s4u2proxy,cn=etc",
                "container_automount" : "cn=automount",
                "ca_host" : "vm.example.com",
@@ -942,7 +941,6 @@
                "enable_ra" : true,
                "container_trusts" : "cn=trusts",
                "container_policygroups" : "cn=policygroups,cn=configs,cn=policies",
-               "session_auth_duration" : "20 minutes",
                "container_realm_domains" : "cn=Realm Domains,cn=ipa,cn=etc",
                "in_tree" : false,
                "realm" : "DOM.EXAMPLE.COM",