Tax category image delete link gone

The "Delete" button next to the image that can be seen in the Help file for the Tax Category window is absent in (at least my) production version of HikaShop, Business 1.5.4.

It is showing the default image for the shop which in this case is absolutely irrelevant.

In any case, I don't know why anyone would want an image associated with a tax category, maybe this feature could be eliminated altogether?

But I'm happy either way, I'd just like the opportunity to get rid of an inappropriate image!

Thanks