Fix due to the modified Close method in WebSocket.cs

Example3/Echo.cs

@@ -13,7 +13,7 @@ namespace Example3
 
     protected override void onClose(object sender, CloseEventArgs e)
     {
-      Console.WriteLine("[Echo] Close({0}: {1})", (ushort)e.Code, e.Code);
+      Console.WriteLine("[Echo] Close({0})", e.Code);
     }
   }
 }