Simplifie la déclaration du favicon

Testé avec Firefox, Opera, Chrome, IE.

app/layout/layout.phtml

@@ -17,8 +17,7 @@
 ?>
 		<link id="prefetch" rel="next prefetch" href="<?php echo Url::display (array ('c' => Request::controllerName (), 'a' => Request::actionName (), 'params' => $params)); ?>" />
 <?php } ?>
-		<link rel="icon" type="image/x-icon" href="<?php echo Url::display ('/favicon.ico'); ?>" />
-		<link rel="icon" type="image/png" href="<?php echo Url::display ('/favicon.ico'); ?>" />
+		<link rel="icon" href="<?php echo Url::display ('/favicon.ico'); ?>" />
 <?php if (isset ($this->rss_url)) { ?>
 		<link rel="alternate" type="application/rss+xml" title="<?php echo htmlspecialchars($this->rss_title, ENT_COMPAT, 'UTF-8'); ?>" href="<?php echo Url::display ($this->rss_url); ?>" />
 <?php } ?>