Add RADIUS proxy support to ipalib CLI

https://fedorahosted.org/freeipa/ticket/3368

ipalib/plugins/config.py

@@ -202,7 +202,7 @@ class config(LDAPObject):
             cli_name='user_auth_type',
             label=_('Default user authentication types'),
             doc=_('Default types of supported user authentication'),
-            values=(u'password',),
+            values=(u'password', u'radius'),
             csv=True,
         ),
     )