Better design of foward screen

Signed-off-by: Jérôme Herbinet <33763786+Jerome-Herbinet@users.noreply.github.com>

templates/forward.php

@@ -4,7 +4,7 @@
 	style('core', 'guest');
 	?>
 
-	<div class="update bbb">
+	<div class="update bbb guest-box">
 		<h2><?php p($_['room']) ?></h2>
 		<p><?php p($l->t('You will be forwarded to the room in the next few seconds.')); ?><br />
 			<br />