message: action: interpret landed state correctly
  This makes sure we can't issue disarm commands while the vehicle is
  landing or taking off.
diff: @@ -422,7 +422,9 @@ void ActionImpl::process_extended_sys_state(const mavlink_message_t &message)
  {
  mavlink_extended_sys_state_t extended_sys_state;
  mavlink_msg_extended_sys_state_decode(&message, &extended_sys_state);
  - if (extended_sys_state.landed_state == MAV_LANDED_STATE_IN_AIR) {
  + if (extended_sys_state.landed_state == MAV_LANDED_STATE_IN_AIR ||
  + extended_sys_state.landed_state == MAV_LANDED_STATE_TAKEOFF ||
  + extended_sys_state.landed_state == MAV_LANDED_STATE_LANDING) {
  _in_air = true;
  } else if (extended_sys_state.landed_state == MAV_LANDED_STATE_ON_GROUND) {
  _in_air = false;
  