Steps to reproduce the issue

I got error when trying to update Joomla from 3.2.1 to 3.2.4: "Blocked Loading Mixed Active Content."
The error was fixed by changing code in "joomlaupdate.php"
$ajax_url = JUri::base() . 'index.php?option=com_installer&view=update&task=update.ajax';
to
$ajax_url = JUri::base(true) . '/index.php?option=com_installer&view=update&task=update.ajax';
and in "administrator/components/com_joomlaupdate/views/update/view.html.php" from
$ajaxUrl = JUri::base().'components/com_joomlaupdate/restore.php';
to
$ajaxUrl = JUri::base(true).'/components/com_joomlaupdate/restore.php';

Expected result

Update Joomla

Actual result

"Blocked Loading Mixed Active Content."

System information (as much as possible)

OS Linux e
PHP 5.3.3
MySQLi 5.1.71
Caching Disabled
GZip Disabled
Firefox 29.0.1
Joomla 3.2.1

Additional comments