[Modify] Polish it

websocket-sharp/WebSocket.cs

@@ -2305,16 +2305,19 @@ namespace WebSocketSharp
       try {
         if (!acceptHandshake ())
           return;
-
-        _readyState = WebSocketState.Open;
       }
       catch (Exception ex) {
-        _logger.Fatal (ex.ToString ());
+        _logger.Fatal (ex.Message);
-        fatal ("An exception has occurred while accepting.", ex);
+        _logger.Debug (ex.ToString ());
+
+        var msg = "An exception has occurred while attempting to accept.";
+        fatal (msg, ex);
 
         return;
       }
 
+      _readyState = WebSocketState.Open;
+
       open ();
     }