Revert "Disable required client authentication on boss"
Revert "Disable required client authentication on boss"

This reverts commit 1aff35674f75b827f54a6f8d7da352e82a8989bb.

Have strict client authentication again since we embed a dummy cert in gPXE now.
The dummy cert buys us practically no extra security but is the most reasonable
solution to the tmcd client auth problem.

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