Error with latest update relating to background-image

On the latest version, the main/wrapping div of the popup has background-image: url(none); as a style if no background image is uploaded.

This gives a console error. Can this be changed to background-image: url(); or something else?

<div id="surbma-yes-no-popup" class="uk-modal surbma-yes-no-popup-normal-centered surbma-yes-no-popup-almost-flat" style="background-image: url(none);background-size: cover;background-repeat: no-repeat;">