Mavlink set last sent timestamp to space out initial publication

- remove QURT defines no longer required

src/modules/mavlink/mavlink_messages.cpp

@@ -405,9 +405,6 @@ protected:
 	explicit MavlinkStreamStatustext(Mavlink *mavlink) : MavlinkStream(mavlink)
 	{}
 
-	~MavlinkStreamStatustext() = default;
-
-
 	bool send(const hrt_abstime t)
 	{
 		if (!_mavlink->get_logbuffer()->empty() && _mavlink->is_connected()) {