Bug 28855: (follow-up) adapt specific test

Bug 28855: (follow-up) adapt specific test

Adapt the test of function DelSuggestionsOlderThan to match the new behaviour of the function.

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
(cherry picked from commit 8d1eaa6a544591a58764dcd636c22d07f3ba57bf)

Signed-off-by: Andrew Fuerste-Henry <andrew@bywatersolutions.com>