Putting PTR records back for analytics100{3,4}.eqiad.wmnet

These machines were given public IPs as they were previously Kafka brokers.
I want to use them for temporary kafkatee consumer testers now, and I'd
rather they have private IPs before we start saving webrequest logs here.

Change-Id: I4f2235c28b233b534b25ca5912d7388dfe73bf65