Update ServerConnectionHandler.java

added Commment for documentation.

server/src/main/java/ch/zhaw/pm2/multichat/server/ServerConnectionHandler.java

@@ -150,7 +150,7 @@ public class ServerConnectionHandler implements Runnable{
                     if (handler != null) {
                         handler.sendData(sender, reciever, type, payload);
                         if(!reciever.equals(sender)){
-                            sendData(sender, reciever, type, payload);
+                            sendData(sender, reciever, type, payload); //send message to sender if it's a direct message and sender is not receiver.
                         }
                     } else {
                         this.sendData(USER_NONE, userName, DATA_TYPE_ERROR, "Unknown User: " + reciever);