chown(2) requires root on every Unix-ish kernel. Restoring 39k files
as a non-root user produces 39k EPERM syscalls plus 39k matching debug
log lines, all for an operation that can't possibly succeed. Skip the
syscall entirely when euid != 0, and emit one warning at the end of the
restore so the user knows the on-disk UID/GID will reflect the running
user rather than the original owner.
sneak
1a97a80a81