Problem description: When a clean zabbix 4.0 installation is opened, in Configuration => Hosts the Zabbix agent interface indicator is red for "Zabbix server" host, as if zabbix agent was unavailable, even though the server wasn't even started at all.

Steps to reproduce:

1. Open a clean installation of the latest Zabbix 4.0, DON'T turn on zabbix server
2. Navigate to Configuration => Hosts

Result: Zabbix agent interface for host Zabbix server is displayed as unavailable (red)

Expected: Because zabbix server wasn't even started yet, Zabbix agent interface should be displayed as unknown (gray).

Example: