fix internet use without cache.json for relative filename
fix internet use without cache.json for relative filename

cgreenhalgh/opensharingtoolkit-kiosk,cgreenhalgh/opensharingtoolkit-kiosk,cgreenhalgh/opensharingtoolkit-kiosk,cgreenhalgh/opensharingtoolkit-kiosk,cgreenhalgh/opensharingtoolkit-kiosk,cgreenhalgh/opensharingtoolkit-kiosk