Landing on a surface with a magnetic anomaly large enough to require the EKF to reset its field states can result in poor heading and large EKF magnetometer and velocity innovations if the vehicle is re-armed and takes off. This happens because the flags indicating that completion of the in-air yaw and field states was not being reset if a ground reset had occurred.
This patch ensures that any reset of magnetic field states that occurs whilst disarmed causes the flags to be reset.