message: fix code warning
diff: @@ -29,8 +29,7 @@ namespace Sqlbi.Bravo.UI.ViewModels
  internal const int SubViewIndex_Progress = 2;
  internal const int SubViewIndex_Changes = 3;
  internal const int SubViewIndex_Finished = 4;
  -
  - DispatcherTimer _timer = new DispatcherTimer();
  + private readonly DispatcherTimer _timer = new DispatcherTimer();
  public DaxFormatterViewModel(IDaxFormatterService formatter, IAnalysisServicesEventWatcherService watcher, ILogger<DaxFormatterViewModel> logger)
  {
  