Bug 19992: use Modern::Perl in Admin perl scripts

Bug 19992: use Modern::Perl in Admin perl scripts

Test plan:
Check use warnings; use strict doesn't exist and use Modern::Perl is written instead in the following files:

admin/admin-home.pl
admin/aqcontract.pl
admin/aqplan.pl
admin/auth_tag_structure.pl
admin/branch_transfer_limits.pl
admin/check_budget_parent.pl
admin/check_parent_total.pl
admin/checkmarc.pl
admin/classsources.pl
admin/clone-rules.pl
admin/didyoumean.pl
admin/edi_accounts.pl
admin/edi_ean_accounts.pl
admin/import_export_framework.pl
admin/item_circulation_alerts.pl
admin/marctagstructure.pl
admin/matching-rules.pl
admin/printers.pl
admin/smart-rules.pl
admin/systempreferences.pl
admin/transport-cost-matrix.pl

Signed-off-by: Jon Knight <J.P.Knight@lboro.ac.uk>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>