takeoff: only set _can_loiter_at_sp if takeoff position has been set

Signed-off-by: RomanBapst <bapstroman@gmail.com>

src/modules/navigator/takeoff.cpp

@@ -149,7 +149,12 @@ Takeoff::set_takeoff_position()
 		memset(rep, 0, sizeof(*rep));
 	}
 
-	_navigator->set_can_loiter_at_sp(true);
+	if (PX4_ISFINITE(pos_sp_triplet->current.lat) && PX4_ISFINITE(pos_sp_triplet->current.lon)) {
+		_navigator->set_can_loiter_at_sp(true);
+
+	} else {
+		_navigator->set_can_loiter_at_sp(false);
+	}
 
 	_navigator->set_position_setpoint_triplet_updated();
 }