Add leeway to rkhunter passive check
Add leeway to rkhunter passive check

Currently 25 hours, but for whatever reason sometimes the job runs a
little later than it should and creates a bunch of alerts which clog up
our monitoring. While it's important to run, I think we're safe to
increase the freshness threshold on this alert.

alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet