Dear Maintainer,

this package installs a systemd service for nagios4 but doesn't enable it.
While directly after the installation of nagios4 it is running, it is
stopped after restarting the machine.

# systemctl status nagios4.service
? nagios4.service - nagios4
      Loaded: loaded (/lib/systemd/system/nagios4.service; disabled;
preset: enabled)
      Active: inactive (dead)
        Docs: man:nagios4