Improve security of sessions:

- use only cookies to store session id on client side
- use default php session system with database handler to store sessions on server side

git-svn-id: http://piwigo.org/svn/trunk@1004 68402e56-0260-453c-a942-63ccdbb3a9ee

include/category_recent_cats.inc.php

@@ -78,7 +78,7 @@ while ( $row = mysql_fetch_array( $result ) )
       'IMAGE_ALT'               => $row['file'],
       'IMAGE_TITLE'             => $lang['hint_category'],
         
-      'U_IMG_LINK'              => add_session_id($url_link)
+      'U_IMG_LINK'              => $url_link
       )
     );