Michael Ablassmeier: libvirt 11.10 VIR_DOMAIN_BACKUP_BEGIN_PRESERVE_SHUTDOWN_DOMAIN

As with libvirt 11.10 a new flag for backup operation has been
inroduced: VIR_DOMAIN_BACKUP_BEGIN_PRESERVE_SHUTDOWN_DOMAIN.

According to the documentation
“It instructs libvirt to avoid termination of the VM if the guest OS shuts down
while the backup is still running. The VM is in that scenario reset and paused
instead of terminated allowing the backup to finish. Once the backup finishes
the VM process is terminated.”

Added support for this in virtnbdbackup 2.40.