http://localhost/affiliate%20alley/wp-admin/admin.php?import=blogger&step=1&_wpnonce=1c8a5e0a37

I am attaching the code where this warning is occurring.

/**
 * Retrieve authors from parsed data
 *
 * @param array $import_data Data returned by a WXR parser
 */
function get_authors_from_import( $import_data ) {

    $feed = $this->parse($import_data);

    $authors = $feed->get_authors();

    foreach ($authors as $author) {
        $login = sanitize_user( $author->get_name(), true );
        $this->authors[$login] = array(
            'author_login' => $author->get_name(),
            'author_display_name' => $author->get_name(),
            'author_email' => $author->get_email(),
        );
    }

I don’t know how can I handle this warning as I am not a coder at all.
Also, this point is to be noted that this warning occurred while I imported my custom domain website as an XML file on wordpress on a website which I have created on my local computer using xampp.