Sanitize.php: allow consecutive underscore in filename

extension/Classes/Core/Helper/Sanitize.php

@@ -222,12 +222,7 @@ class Sanitize {
             $filename = basename($filename);
         }
 
-        $res = preg_replace($search, $replace, $filename);
-
-        // remove multiple consecutive '_'
-        $res = preg_replace('~_+~', '_', $res);
-
-        return $res;
+        return preg_replace($search, $replace, $filename);
     } // safeFilename()
 
     /**