Every 24 hours housekeeping is performed for SNMP cache, however housekeeping blocks scheduling of new checks and waits for current checks to finish, this can be problematic if there are running checks with high timeouts.

Expected:
It is not necessary for regular housekeeping to block scheduling of new checks, it was only needed when clearing whole snmp cache manually because it would clear everything and not only unused checks.
Also when check with large timeout is timed out it would be good to write information about timeout.