Remove DynamicDNS requirement

Theoretically STORJ wouldn’t need DDNS anymore. The node connects to the satellite, which then knows the public IP of the node.
If the IP changes, the node needs to check in with the satellite again to update its IP.
(The satellite knowing the DDNS doesn’t help anyway because with an IP change, it has to wait for the DUC to update the DDNS entry. So the node updating its own IP entry on the satellite would be the same thing and also reduce the DNS requests the satellite will be doing)
The uplinks get their IP-lists from the satellite anyway.
Therefore there would actually be no need for DDNS anymore, which would make setting up nodes a lot easier.

However, correct port-forwarding on the router would stil be a requirement and a real public IP address too. Removing DDNS doesn’t mean that nodes behind some ISP NAT would suddenly work.