Steps to reproduce:

1. Open zabbix_server.conf
2. Add HistoryProvider with empty value, or with missing some of the options:

   HistoryProvider=

3. Test the configuration: zabbix_server -T (or --test-config)
4. See that validation is succesful
5. Start the server

Result:
Server fails, message in the log:

428809:20260916:145102.521 cannot initialize history storage: invalid HistoryProvider value ""

Expected:
The validation should fail.