When running as an admin, fetch locally on boss instead of on ops, so that we can handle images in /usr/testbed/images.
When running as an admin, fetch locally on boss instead
of on ops, so that we can handle images in /usr/testbed/images.

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