Update domain.txt
Update domain.txt

Root domains to detect from #4416 . ```NS``` and ```SOA``` records are related to ```dnspod.net``` , which lives in https://github.com/stamparm/maltrail/blob/master/trails/static/suspicious/dnspod.txt
stamparm/maltrail,stamparm/maltrail,stamparm/maltrail,stamparm/maltrail