Update of serverconfig ipaconfigstring options

Patch "Add options to reduce writes from KDC" adds two more possible values to config plugins ipaconfigstring configuration options.

These are:
 * KDC:Disable Last Success
 * KDC:Disable Lockout

This patch adds them to Web UI

https://fedorahosted.org/freeipa/ticket/2734

install/ui/serverconfig.js

@@ -62,7 +62,10 @@ IPA.config.entity = function(spec) {
                         {
                             name: 'ipaconfigstring',
                             type: 'checkboxes',
-                            options: IPA.create_options(['AllowLMhash','AllowNThash'])
+                            options: IPA.create_options([
+                                'AllowLMhash', 'AllowNThash',
+                                'KDC:Disable Last Success', 'KDC:Disable Lockout'
+                            ])
                         },
                         {
                             type: 'checkbox',