Wrap previous change in check for MAINSITE, and only when running from the main tree. This will prevent devel trees from running Rob's alternate version.
Wrap previous change in check for MAINSITE, and only when running from
the main tree. This will prevent devel trees from running Rob's
alternate version.

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