FlightTaskOrbit: switch to FlightTaskAltitudeSmooth

Nice smooth altitude control is already provided by the existing
flight task for altitude mode. We inherit from it to resuse the
functionality and just all its update first not altering the setpoints
for the z-axis it produced.

src/lib/FlightTasks/tasks/FlightTaskOrbit.hpp

@@ -41,9 +41,9 @@
 
 #pragma once
 
-#include "FlightTaskManual.hpp"
+#include "FlightTaskManualAltitudeSmooth.hpp"
 
-class FlightTaskOrbit : public FlightTaskManual
+class FlightTaskOrbit : public FlightTaskManualAltitudeSmooth
 {
 public:
 	FlightTaskOrbit();