Check_MK Werk 4433: Fixed freshness and staleness for always-up and cluster hosts.

ID: 4433 Title: Fixed freshness and staleness for always-up and cluster hosts. Component: Core & setup Level: 1 Class: Bug fix Version: 1.5.0i1 Host which should be considered always-up and cluster hosts had wrong freshness and staleness values: They were effectively only checked once, but never again, so they were considered unfresh and stale after some time. This has been fixed.