Bug 8710 - Don't show the images tab in the OPAC if the record has no local images

Bug 8710 - Don't show the images tab in the OPAC if the record has no local images

For unknown reasons, having ListImagesForBiblio return undef
when there are no images still results in a variable being passed
to the template which evaluates as true, with a size of 1.

This patch alters ListImagesForBiblio to remove the "return undef"
condition, allowing the template to evaluate images as false
and show no tab.

To test, turn on local cover images and view records in the OPAC
which do and do not have cover images attached. Images should
display as expected when present, and no images tab should appear
on records which have none.

Signed-off-by: Melia Meggs <melia@test.bywatersolutions.com>
Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Jared Camins-Esakov <jcamins@cpbibliography.com>