Missing artwork Bug after "Cache artwork paths" Commit

[randombyt]

A bug has been introduced after "Cache artwork paths" commit. When an artwork is missing, the last available artwork is shown rather then showing it empty. This also ignores place-holder items for missing artwork.

This is only happening with artwork, calling artwork directly (fe.add_image) does not exhibit this behavior and works normally i.e. empty is shown empty and last available image is not used.

This is similar to issue #499

[mickelson]

Thanks for finding that, it should be fixed now