Cannot add a custom favicon anymore

Steps to reproduce (using http://www.xwiki.org/xwiki/bin/view/FAQ/How+do+I+add+a+favicon+for+my+wiki) :

• attach a new favicon named "icons.xwiki.favicon.ico" on the skin XWiki.DefaultSkin
• refresh the homepage of the wiki
  Expected result:
• the URL should be updated to (results from 6.2.4):

  <link href="/xwiki/bin/skin/XWiki/DefaultSkin/icons.xwiki.favicon.ico" rel="shortcut icon">
  

• the favicon is displayed on the browser tab

Actual result:

• the favicon is not displayed on the browser tab
• the URL is still the default one:

  <link href="/xwiki/resources/icons/xwiki/favicon.ico" rel="shortcut icon">