Fix a problem diagnosed by Tim.  Vnodes with no experimental IFs were botching their sshd setup due to some code I added.
Fix a problem diagnosed by Tim.  Vnodes with no experimental IFs were
botching their sshd setup due to some code I added.

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