ui: user view: disable 'Unlock TFA' button by default

Without this, the button is enabled if no entry at all is selected (e.g.
when switching to the 'User Management' tab), with the button then
(obviously) being a noop.

Signed-off-by: Christoph Heiss <c.heiss@proxmox.com>

www/config/UserView.js

@@ -186,6 +186,7 @@ Ext.define('PBS.config.UserView', {
 	    xtype: 'proxmoxButton',
 	    text: gettext('Unlock TFA'),
 	    handler: 'unlockTfa',
+	    disabled: true,
 	    enableFn: ({ data }) =>
 	        data['totp-locked'] || (data['tfa-locked-until'] > (new Date().getTime() / 1000)),
 	},