Comment 12 for bug 1646585

The latest ubiquity I see for xenial is 2.21.63, and its netcfg-common.c looks unfixed:

void reap_old_files (void)
{
    static char* remove[] =
        { INTERFACES_FILE, HOSTS_FILE, HOSTNAME_FILE, NETWORKS_FILE,
          RESOLV_FILE, DHCLIENT_CONF, DOMAIN_FILE, 0 };
    char **ptr = remove;

    while (*ptr)
        unlink(*ptr++);
}