[Modify] Replace it

websocket-sharp/Server/WebSocketServer.cs

@@ -599,10 +599,7 @@ namespace WebSocketSharp.Server
           throw new InvalidOperationException (msg);
         }
 
-        if (_sslConfig == null)
+        return getSslConfiguration ();
-          _sslConfig = new ServerSslConfiguration ();
-
-        return _sslConfig;
       }
     }