Removed an assertion that prevents multiple transport listeners

src/de/tud/kom/p2psim/impl/transport/modular/ModularTransLayer.java

@@ -543,8 +543,6 @@ public class ModularTransLayer implements SimHostComponent, TransportComponent,
 
 		public void addListener(TransMessageListener listener) {
 			if (!transListeners.contains(listener)) {
-				// just checking, if multiple happens at all
-				assert transListeners.isEmpty();
 				transListeners.add(listener);
 			}
 		}