Fix: schemas: False positives in best-match.sh

The list_candidates() function is too lax and matches
pacemakerd-health-2.25.rng when it looks for candidates for pacemakerd.

This caused an api-result.rng compile failure when updating to API
version 2.26. Somehow it doesn't seem to cause issues on 2.25.

Signed-off-by: Reid Wahl <nrwahl@protonmail.com>