message: ignore session_stats_header_alert from the alerts stream
diff: @@ -1071,6 +1071,11 @@ public class SessionManager {
  alert a = v.get(i);
  int type = a.type();
  + // ignore session_stats_header_alert
  + if (type == session_stats_header_alert.alert_type) {
  + continue;
  + }
  +
  Alert<?> alert = null;
  switch (AlertType.fromSwig(type)) {
  