INT_TIME define added

lib/treppe/treppe.cpp

@@ -130,7 +130,7 @@ void Treppe::task()
 }
 
 void Treppe::berechne_dimmer() {
-    ticks_pro_stufe = time_per_stair / 20; // [ms]
+    ticks_pro_stufe = time_per_stair / INT_TIME; // [ms]
     differenz_pwm_pro_tick = (float) (active_brightness - idle_brightness) 
                                         / (float) ticks_pro_stufe;
 }