https://pagure.io/fedora-infrastructure/issue/12531

This has been done before, but Copr hypervisors stopped allocating VMs, observing several problems

• inability to boot VMs (ppc64le p08 boxes)
• inability to ssh-connect to newly started VMs over ipv6
• no ipv4 internet on allocated VMs (through libvirt's NAT), even though ipv6 worked

Reverting to iptables && libvirtd restart helped the situation:
https://pagure.io/fedora-infra/ansible/c/43b8ee52d8b05acb22a8128d4b9fe207707bea82..43b8ee52d8b05acb22a8128d4b9fe207707bea82

Goot for now, but we should align with the rest of the Fedora hypervisors and move to nftables.