Mixed Content Fixer

mixed_content_fixer.php

<?php
/* Plugin Name: Mixed Content Fixer
* Description: This simple plug-in is replacing the url's in content from http to https. 
* Author: Leo Seccia & Dejan Markovic
* Version: 2014.1.0
*/

add_filter('the_content', 'content_fix');
function content_fix($content)
{
    if (is_ssl()) {
        return  str_replace("http://", "https://", $content);
    }
    else
    {
        return $content;
    }
}