Changed index.php file in uploads folder

The previous index.php in wp-content/uploads

<?php
// GNU General Public License

has become this (maybe from the upgrade to 4.7):

<?php
/**
 * Front to the WordPress application. This file doesn't do anything, but loads
 * wp-blog-header.php which does and tells WordPress to load the theme.
 *
 * @package WordPress
 */

/**
 * Tells WordPress to load the WordPress theme and output it.
 *
 * @var bool
 */
define('WP_USE_THEMES', true);

/** Loads the WordPress Environment and Template */
require( dirname( __FILE__ ) . '/wp-blog-header.php' );

Wordfence has flagged it as malicious. It doesn’t look threatening but should I worry? I think I’ll change it back anyway.