Tor does not ignore unknown managed proxy output

Tor marks a managed proxy as broken when it receives unknown output from it.

This is bad for forward compatibility. The 180 spec also wants managed proxies to ignore unknown output:

  Tor MUST ignore lines with keywords that it doesn't recognize.

In src/or/transports.c:

  log_warn(LD_CONFIG, "Unknown line received by managed proxy. (%s)", line);

 err:
  mp->conf_state = PT_PROTO_BROKEN;
  log_warn(LD_CONFIG, "Managed proxy at '%s' failed the configuration protocol"
           " and will be destroyed.", mp->argv[0]);
}