Bug 23696: take deleted biblios into account when building oai sets

Bug 23696: take deleted biblios into account when building oai sets

Test plan:
0) do not apply the patch
1) set up OAI and create at least one set
2) run build_oai_sets.pl
3) remember/write down number of records added
4) delete a biblio, the is included in set
5) run buid_oai_sets.pl again
6) the set is 1 record smaller
7) apply the patch
8) run build_oai_sets.pl
9) the number of record should be the same as in 3)

Signed-off-by: Michal Denar <black23@gmail.com>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>