Fix Session Storage when using None.

<a href="https://github.com/joomla/joomla-platform/commit/7b31e884dc01b136a85f9602c5c0acd5e6cd4be8#libraries/joomla/session/storage/none.php">This commit</a> in the Platform should have removed only the <code>ini_set('session.save_handler', 'files'); </code> line, leaving the register() method empty. As a result of removing the entire method the session is cleared every time getSession() from Factory is called.