Lightgallery not started due to "Uncaught ReferenceError: id is not defined"

When a page is loaded containing one or more lightgalleries a javascript is triggered:

Uncaught ReferenceError: id is not defined

This causes not initiating the lightgallery for the element.

The error is within the js/lightgallery_load.js file; the variable id is used before being declared.

      for (id in settings.lightgallery.instances) {
        // Store galleries so that developers can change options.
        that.galleries[id] = settings.lightgallery.instances[id];
        _lightgallery_init(id, that.galleries[id], context);
      }

Adding var before the id fixed the issue:

      for (var id in settings.lightgallery.instances) {
        // Store galleries so that developers can change options.
        that.galleries[id] = settings.lightgallery.instances[id];
        _lightgallery_init(id, that.galleries[id], context);
      }