message: Fix a crash if user tries to toggle bookmark with no capture loaded
diff: @@ -969,6 +969,7 @@ void EventBrowser::events_contextMenu(const QPoint &pos)
  expandAll.setEnabled(item && item->childCount() > 0);
  collapseAll.setEnabled(item && item->childCount() > 0);
  + toggleBookmark.setEnabled(m_Ctx.IsCaptureLoaded());
  QObject::connect(&expandAll, &QAction::triggered,
  [this, item]() { ui->events->expandAllItems(item); });
  