Bug 19319: (QA follow-up) Biblionumber leftovers in opac-detail.tt

Bug 19319: (QA follow-up) Biblionumber leftovers in opac-detail.tt

Correcting a few biblionumber template var leftovers in opac-detail
template. They were combined with url filter instead of html.

Test plan:
[1] Look for [^.;?]biblionumber in opac-detail.tt and verify that these
    occurrences are fine.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>