message: make the render statistics window a static size
diff: @@ -626,7 +626,10 @@ namespace ospray {
  void ImGuiViewer::guiRenderStats()
  {
  - ImGui::Begin("Rendering Statistics", nullptr, g_defaultWindowFlags);
  + ImGui::SetNextWindowSize(ImVec2(255,165), ImGuiCond_Always);
  +
  + auto flags = g_defaultWindowFlags | ImGuiWindowFlags_NoResize;
  + ImGui::Begin("Rendering Statistics", nullptr, flags);
  ImGui::NewLine();
  ImGui::Text("OSPRay render rate: %.1f fps", lastFrameFPS);
  