message: Help menu tweaks
diff: @@ -603,7 +603,9 @@ namespace ospray {
  void ImGuiViewer::guiMainMenuHelp()
  {
  if (ImGui::BeginMenu("Help")) {
  - ImGui::Checkbox("About", &showWindowAbout);
  + if (ImGui::MenuItem("About"))
  + showWindowAbout = true;
  + ImGui::Separator();
  ImGui::Checkbox("Show ImGui Demo", &showWindowImGuiDemo);
  ImGui::EndMenu();
  