csharp: added request timeout for download

web/documentserver-example/csharp/TrackManager.cs

@@ -324,6 +324,7 @@ namespace OnlineEditorsExample
             if (string.IsNullOrEmpty(path)) throw new ArgumentException("path");  // file isn't specified
 
             var req = (HttpWebRequest)WebRequest.Create(url);
+            req.Timeout = 5000;
             using (var stream = req.GetResponse().GetResponseStream())  // get input stream of the file information from the url
             {
                 if (stream == null) throw new Exception("stream is null");