[Web] remove u2f lib from prerequisites

data/web/inc/prerequisites.inc.php

@@ -46,9 +46,7 @@ require_once $_SERVER['DOCUMENT_ROOT'] . '/inc/lib/CSSminifierExtended.php';
 
 require_once $_SERVER['DOCUMENT_ROOT'] . '/inc/lib/array_merge_real.php';
 
-// U2F API + T/HOTP API
-// u2f - deprecated, should be removed
-$u2f = new u2flib_server\U2F('https://' . $_SERVER['HTTP_HOST']);
+// T/HOTP API
 $qrprovider = new RobThree\Auth\Providers\Qr\QRServerProvider();
 $tfa = new RobThree\Auth\TwoFactorAuth($OTP_LABEL, 6, 30, 'sha1', $qrprovider);