In my earlier commit
manual: Don't suggest exposing VM port to local network.
I made a side change titled
Use `127.0.0.1` also on the VM side, otherwise connections to
services that, in the VM, bind to `127.0.0.1` only
(doing the safe approach) do not work.
Unfortunately, that was wrong:
QEMU inside the VM always communicates via the virtualised
Ethernet interface, not via the VM's loopback interface.
So trying to connect to `127.0.0.1` on the VM's side cannot work.
