[Modify] Polish it

websocket-sharp/Net/WebSockets/TcpListenerWebSocketContext.cs

@@ -283,11 +283,12 @@ namespace WebSocketSharp.Net.WebSockets
     public override IEnumerable<string> SecWebSocketProtocols {
       get {
         var protocols = _request.Headers["Sec-WebSocket-Protocol"];
-        if (protocols != null)
+        if (protocols != null) {
           foreach (var protocol in protocols.Split (','))
             yield return protocol.Trim ();
         }
       }
+    }
 
     /// <summary>
     /// Gets the value of the Sec-WebSocket-Version header included in the request.