For !badexit rules we do not need to touch bad.conf

When applying badexit rules to relays we do so only per fingerprint and not per IP address nowadays. Thus, we don't need any AuthDirBadExit for now/anymore. I think we can outright remove that part for the time being. If, for some reason, we actually want to use AuthDirBadExit at some point in the future again we could re-introduce it behind some command-line switch.