Problem description: If there is a disabled Host that belongs to a Host group that is in maintenance, the "Host availability" widget doesn't display this host under "Unknown" and "Total" fields, if the "Show hosts in maintenance" option is not checked. In such a way zabbix is indicating that this disabled host is in maintenance, but in consistency with the decisions made within ZBXNEXT-5163, it shouldn't, in order not to confuse users that a disabled hosts is going into maintenance.

Steps to reproduce:

1. Navigate to Configuration => Hosts .
2. Create a Host linked to a Host group.
3. Disable this Host.
4. Navigate to Monitoring => Dashboards and open any dashboard
5. Add a "Host availability" widget to the dashboard - set the "Show hosts in maintenance" option and define the host group that Your host belongs to in "Host groups" field.
6. Verify that Your host is counted in "Unknown" field.
7. Navigate to Configuration => Maintenance and create a maintenance period for the Host group that Your Host belongs to.
8. Once the maintenance is active, navigate to Monitoring => Dashboards and edit the "Host availability" widget - unset the "Show hosts in maintenance" option.
9. Open the dashboard with the updated "Host availability" widget

Result: After unsetting the "Show hosts in maintenance" option the Disabled Host that belongs to a Host group in maintenance is not taken into account in the "Unknown" and "Total" fields of the "Host availability" widget

Expected: we should avoid confusing users that a disabled host is able to go in maintenance, therefore, to be consistent, also the "Host availability" widget should count such disabled hosts in "Unknown" and "Total" fields even if the corresponding host group is in maintenance.

Example: