Zabbix

.......PS. [ZBX-10983] fixed crash in IPMI poller, added deleting of inactive IPMI hosts in 'unreachable poller', improved code correctness and debug logging

This change:
   - fixes crash of IPMI poller when deleting an inactive IPMI host,
   - fixes bug when closing an inactive host with domain already closed deletes sensors and controls for other host,
   - fixes potential use of stale pointers,
   - adds deleting of inactive IPMI hosts in 'unreachable poller',
   - improves debug logging for IPMI functions.