Workaround to implement Google-Analytics script

ga.php

<?php
/**
 * Google-Analytics
 * Do not forget to replace te ID (UA-00000000-0)
 */

$alternate = '(function(root){
            root.GoogleAnalyticsObject = "ga";
            root.ga = {q: [["create", "UA-00000000-0", "auto"]],l: 1 * new Date()};
        })(this);';

function get_url($url)
{
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_HTTPHEADER, array(
        'Content-type: application/javascript'
    ));
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($ch, CURLOPT_FRESH_CONNECT, 1);
    curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 0);
    curl_setopt($ch, CURLOPT_TIMEOUT, 5); //timeout in seconds
    $content = curl_exec($ch);
    curl_close($ch);
    return $content;
}

function get_content($file, $url, $hours = 24, $fn = '', $fn_args = '')
{
    $current_time = time();
    $expire_time = $hours * 60 * 60;
    $file_exists = file_exists($file);

    if ($file_exists)
    {
        $file_time = filemtime($file);
    }

    if ($file_exists && ($current_time - $expire_time < $file_time))
    {
        $content = file_get_contents($file);
        $content.= '/* cachedtype: js */';
    }
    else
    {
        $content = get_url($url);
        if ($content && $fn)
        {
            $content = $fn($content, $fn_args);
        }
        if ($content)
        {
            $content.= '/* cachedtime: ' . time() . ' */';
            file_put_contents($file, $content);
        }
    }
    return $content;
}

function get_script($file, $url)
{
    global $alternate;

    $time = time();
    $response = get_content($file, $url);

    if ($response === false)
    {
        $response = $alternate;
    }

    $headers = array(
        'Content-Type' => 'application/javascript',
        'Last-Modified' => gmdate('D, d M Y H:i:s T', $time) ,
        'Expires' => gmdate('D, d M Y H:i:s T', strtotime('+30 days', $time)) ,
        'Cache-Control' => 'public',
    );

    header("HTTP/1.1 200 OK");

    foreach ($headers as $key => $value)
    {
        header($key . ':' . $value);
    }

    echo $response;
}

get_script('ga.js', 'https://www.google-analytics.com/analytics.js');

die();