I restored all the servers.
The freeciv-debian.ns0.it virtual machine was entirely unaffected by the crash, which occurred this Wednesday between 09:17 and 09:27 UTC.
Instead, three of the Greatturn servers – GT08, 09, 10-Africa – were disrupted by the crash. I have restored these, and their turns will advance synchronized in two days, this Sunday, 18:00 UTC.
If anything has not been correctly restored as intended, let me know.