At the OPAC we already had a verify_images JS function in amazonimages.js
It's preferable to use another function name.
This patch replace our verify_images with verify_cover_images and apply
the change to the staff code as well.
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>