Undefined property: kdMultipleFeaturedImages::$args

The notice refers line #69 of the "multiple-featured-images.php" file.
Actually the following line:

    $this->nonce        = 'mfi-'.$this->args['id'].$this->args['post_type'];

should be:

    $this->nonce        = 'mfi-'.$args['id'].$args['post_type'];

I can't create a pull request right now but i'll will do it ASAP.

Thanks for your plugin: really useful :+1: