fix commander: set _have_taken_off_since_arming when !landed upon arming

If arming and already !landed, _have_taken_off_since_arming will not be set
and thus auto-disarm after 10s will be triggered (with default config).

This can only happen due to quick state changes, as land detector generally
sets landed=true if !armed.

src/modules/commander/Commander.cpp

@@ -2189,7 +2189,12 @@ Commander::run()
 		if (_was_armed != armed.armed) {
 			_status_changed = true;
 
-			if (!armed.armed) { // increase the flight uuid upon disarming
+			if (armed.armed) {
+				if (!_land_detector.landed) { // check if takeoff already detected upon arming
+					_have_taken_off_since_arming = true;
+				}
+
+			} else { // increase the flight uuid upon disarming
 				const int32_t flight_uuid = _param_flight_uuid.get() + 1;
 				_param_flight_uuid.set(flight_uuid);
 				_param_flight_uuid.commit_no_notification();
@@ -2198,6 +2203,11 @@ Commander::run()
 			}
 		}
 
+		if (!armed.armed) {
+			/* Reset the flag if disarmed. */
+			_have_taken_off_since_arming = false;
+		}
+
 		_was_armed = armed.armed;
 
 		/* now set navigation state according to failsafe and main state */
@@ -2359,11 +2369,6 @@ Commander::run()
 
 		_status_changed = false;
 
-		if (!armed.armed) {
-			/* Reset the flag if disarmed. */
-			_have_taken_off_since_arming = false;
-		}
-
 		arm_auth_update(now, params_updated || param_init_forced);
 
 		px4_usleep(COMMANDER_MONITORING_INTERVAL);