Bug 8916: Hide Curriculum index in advanced search if marcflavor = unimarc

Bug 8916: Hide Curriculum index in advanced search if marcflavor = unimarc

This patch hides curriculum option value in koha-tmpl/intranet-tmpl/prog/en/includes/search_indexes.inc and koha-tmpl/opac-tmpl/prog/en/modules/opac-advsearch.tt if marcflavor = UNIMARC

To test
- set marcflavour to UNIMARC, this option should be hidden in the index list in opac and staff interface advanced search
- set marcflavour to MARC21, this option should be visible, as before

Signed-off-by: Chris Cormack <chris@bigballofwax.co.nz>
Signed-off-by: Paul Poulain <paul.poulain@biblibre.com>