docs: function remove(conf) {
    var file = conf.get(ConfigKey.PIDFILE);
    // can be the empty string
    if(file) {
      log.notice('removing pid file %s', file);
      try {
        fs.unlinkSync(file);
      }catch(e) {
        log.warning('failed to remove pid file (%s): %s', file, e.message);
      }
    }
  }