[Plugin: Hot Linked Image Cacher] Images not uploading to media path

I have put in Media Setting that images should be uploaded to http://img.domain.tld but this plugin puts my images in http://domain.tld/img/ instead.

I believe it has something to do with this line of code inside hotlinked-image-cacher.php

$httppath = get_option('siteurl') . "/".$upload_dir;

I want to replace the code above about so it will call the the full url path to media files.

Please help. Thanks in advance.