Probe firmware version 4470

• This firmware fixes two bugs.
  • The first one is that DNS results may get mixed up when a probe runs two DNS measurements at the same time.
  • The second one is where traceroute sometimes reports a timestamp of 0.
• In addition, the firmware now has IPv6 literals for the registrations servers, so an IPv6-only probe can connect to a registration server even if it doesn't have a DNS resolver.