Steps to reproduce:
- Configure a net.dns item to point to a DNS server 192.168.10.10
- Kill the DNS server process on 192.168.10.10
- The item becomes "unsupported" with
The item should return "0" according to documentation, and not become unsupported.
Link to documentation: https://www.zabbix.com/documentation/current/en/manual/config/items/itemtypes/zabbix_agent