disable speculat peak by default

GUI/Model/Sim/SimulationOptionsItem.h

@@ -66,7 +66,7 @@ private:
     bool m_computation_method_analytical = true;
     unsigned m_number_of_monte_carlo_points = 100;
     bool m_use_average_materials = true;
-    bool m_include_specular_peak = true;
+    bool m_include_specular_peak = false;
     bool m_use_meso_reciprocal_sum = false;
     double m_meso_radius_factor = 2.1;
     bool m_use_dataset = true;