WebDevStudios/Custom-Metaboxes-and-Fields-for-WordPress — pull request #639 by Blindmikey (2014-07-31 17:24:50+00:00)
Title: Modified get_meta_box_url() to return a protocol agnostic uri

HTTPS environments fail to load the asset on certain browsers due to http:// being a part of the uri. By being protocol agnostic, we play well with all environments.