Add another part to node_status - move plab phys nodes that have not checked in for a while into hwdown.
Add another part to node_status - move plab phys nodes that have not
checked in for a while into hwdown.

Adding another query to do this was much simpler than trying to make the one
monster query already in this script get what we wanted.

nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome