Bug 9468: make av-build-dropbox.inc available to OPAC

Bug 9468: make av-build-dropbox.inc available to OPAC

This patch makes the av-build-dropbox.inc template include introduced
by the latest patches for bug 766 available to the prog and Bootstrap
themes in the OPAC.

See later patches in this series for testing.

Signed-off-by: Galen Charlton <gmc@esilibrary.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Amended patch: Remove OPAC prog file

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>