Errors when used on galleries with mixed content

[vwong]

On galleries with mixed image and video content, this plugin raises exceptions when the current slide is not an image.

The error appears to originate from

lg-zoom.js/src/lg-zoom.js

Line 89 in ed531a9

var image = _this.core.outer.querySelector('.lg-current .lg-image');

Where the query selector fails, var image is undefined, raising errors when trying to read image.clientWidth and image.clientHeight. Should there be a guard against non-image slides?