Without a migration address libvirt sends a migrating VM to the
destination's own host name, which the source host often cannot resolve:
a live migration to a host added without one failed ("Unable to resolve
address ..."), also when the other host had one. The destination's
address on the Computes page, which the panel reaches it at, is now the
default; the migration address stays for another network. A host the
panel reaches on its loopback keeps libvirt's default.
