Fatal error

Hello,
I have a blog http://hotspotbulgaria.com/.
Since yesterday I receive Fatal error: Call to undefined function define() in /home/hotspotb/public_html/index.php on line 14

I think the problem is in a plugin for mobile theme. I cant access admin panel to remove the plugin, so I delete it through ftp connection.

Unfortunately there was no effect. Index.php file is:

<?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('./wp-blog-header.php');

So line 14 is define(‘WP_USE_THEMES’, true);

Even worse is that the last backup is from 1 2 months ago. Is there any possibility to bring back the web page to normal state?