Bug 16224: Fix t/db_dependent/Reports_Guided.t

Bug 16224: Fix t/db_dependent/Reports_Guided.t

This test:

is( scalar @{ get_saved_reports( $report_ids[0] ) }, 1,
"filter takes report id" );

can fail when $report_ids[0] is a substring of some saved_sql fields
from other reports (reports that have a different id than
$report_ids[0]).
We can only be sure that get_saved_reports will return at least 1
report.

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Brendan Gallagher <bredan@bywatersolutions.com>