removing initiator from audience for events sent via mail

Signed-off-by: Stephan Richter <s.richter@srsoftware.de>

messages/src/main/java/de/srsoftware/umbrella/message/MessageSystem.java

@@ -173,7 +173,9 @@ public class MessageSystem extends BaseHandler implements PostBox, EventListener
 	@Override
 	public void onEvent(Event<?> event) {
 		var message = new TranslatableMessage(event.initiator(),event.subject(),event.describe(),null);
-		send(new Envelope<>(0,message,event.audience()));
+		var audience = new HashSet<>(event.audience());
+		audience.remove(event.initiator());
+		send(new Envelope<>(0,message,audience));
 	}
 
 	private boolean patchSettings(HttpExchange ex, UmbrellaUser user) throws IOException {