lib/model: Fix minor flakiness in TestModTimeWindow
lib/model: Fix minor flakiness in TestModTimeWindow

syncthing/syncthing,syncthing/syncthing,wweich/syncthing,wweich/syncthing,wweich/syncthing,imsodin/syncthing,imsodin/syncthing,wweich/syncthing,syncthing/syncthing,syncthing/syncthing,syncthing/syncthing,imsodin/syncthing,syncthing/syncthing,imsodin/syncthing,imsodin/syncthing