RTL: use loiter radius from mission for loiter before enganging mission in RTL

Signed-off-by: Silvan Fuhrer <silvan@auterion.com>

src/modules/navigator/mission.cpp

@@ -442,6 +442,7 @@ Mission::find_mission_land_start()
 			_landing_start_lon = missionitem.lon;
 			_landing_start_alt = missionitem.altitude_is_relative ?	missionitem.altitude +
 					     _navigator->get_home_position()->alt : missionitem.altitude;
+			_landing_loiter_radius = missionitem.loiter_radius;
 			_land_start_available = true;
 		}