Readme: Remove broken link to retired Windows app
Readme: Remove broken link to retired Windows app

OpenSprinkler/OpenSprinkler-App,PeteBa/OpenSprinkler-App,OpenSprinkler/OpenSprinkler-App,PeteBa/OpenSprinkler-App,OpenSprinkler/OpenSprinkler-App,PeteBa/OpenSprinkler-App