Set default set_publlish() argument to true.

src/modules/simulator/simulator.h

@@ -344,7 +344,7 @@ private:
 	void send_controls();
 	void send_heartbeat();
 	void send_mavlink_message(const mavlink_message_t &aMsg);
-	void set_publish(const bool publish = false);
+	void set_publish(const bool publish = true);
 	void update_sensors(mavlink_hil_sensor_t *imu);
 	void update_gps(mavlink_hil_gps_t *gps_sim);