[Bug] Brand image previews doesn't work

[bindermuehle]

Brand image previews are not rendered unless I load following command in a javascript file: $(document).previewUploadedImage('#loevgaard_sylius_brand_brand_images');

This can be done in the browser console to test.

I assume that this is a new bug since this bug has been solved before. If you can confirm this bug I can provide a PR to solve it.

[loevgaard]

Would very much appreciate a PR :-)