message: fix admin formatting bug
diff: @@ -113,9 +113,9 @@ void AdminImpl::addOutlierInfo(const std::string& cluster_name,
  const Upstream::Outlier::Detector* outlier_detector,
  Buffer::Instance& response) {
  if (outlier_detector) {
  - response.add(fmt::format("{}::outlier::success_rate_average::{}", cluster_name,
  + response.add(fmt::format("{}::outlier::success_rate_average::{}\n", cluster_name,
  outlier_detector->successRateAverage()));
  - response.add(fmt::format("{}::outlier::success_rate_ejection_threshold::{}", cluster_name,
  + response.add(fmt::format("{}::outlier::success_rate_ejection_threshold::{}\n", cluster_name,
  outlier_detector->successRateEjectionThreshold()));
  }
  }
  