pve-manager failed installation when FQDN used as hostname

[dhrinkino]

During installation hostnamectl set-hostname set hostname, but i found in few times only saved last subdomain as hostname. (example FQDN was hv.rpi.example.tld and hostname was hv) This caused failed in pve-manager configuration because only FQDN was set in /etc/hosts and system doesn't resolve real hostname(hv for example). Potentional fix can be creating record in /etc/hosts with output from variable HOSTNAME, and via awk get last subdomain and assign this domain to same record.