removed functions provided for php backward compatibility as 5.2 is now required

git-svn-id: http://piwigo.org/svn/trunk@27152 68402e56-0260-453c-a942-63ccdbb3a9ee

include/common.inc.php

@@ -73,10 +73,6 @@ $header_notes = array();
 $filter = array();
 
 foreach( array(
-  'array_intersect_key', //PHP 5 >= 5.1.0RC1
-  'hash_hmac', //(hash) - enabled by default as of PHP 5.1.2
-  'preg_last_error', // PHP 5 >= 5.2.0
-  'json_encode', // PHP 5 >= 5.2.0
   ) as $func)
 {
   if (!function_exists($func))