set_variable depreciated in 2.6.0 causes error in function manage_notifications

[Gnative]

Fixed by adding ee_version check to construct

    //normal
    if (defined('APP_VER'))
    {
        $this->ee_version = APP_VER;
    }
    //install wizard
    else if (isset(ee()->version))
    {
        $this->ee_version = ee()->version;
    }

And in manage_notifications function

    //set_variable depracated in 2.6.0
    if (version_compare($this->ee_version, '2.6.0', '>='))
    {
        $this->EE->view->cp_page_title = 'Manage Notifications';
    }
    else
    {
        $this->EE->cp->set_variable('cp_page_title', 'Manage Notifications');
    }

[heymarkreeves]

Thanks! Could you do a pull request so I can get your code directly?