Add the list of PKINIT servers as a virtual attribute to global config

https://pagure.io/freeipa/issue/6937

Reviewed-By: Jan Cholasta <jcholast@redhat.com>
Reviewed-By: Stanislav Laznicka <slaznick@redhat.com>

ipaserver/plugins/config.py

@@ -255,6 +255,12 @@ class config(LDAPObject):
             doc=_('Renewal master for IPA certificate authority'),
             flags={'virtual_attribute', 'no_create'}
         ),
+        Str(
+            'pkinit_server_server*',
+            label=_('IPA master capable of PKINIT'),
+            doc=_('IPA master which can process PKINIT requests'),
+            flags={'virtual_attribute', 'no_create', 'no_update'}
+        ),
         Str(
             'ipadomainresolutionorder?',
             cli_name='domain_resolution_order',