fix media cache file backend, correctly return contents
fix media cache file backend, correctly return contents

nsams/koala-framework,Sogl/koala-framework,Sogl/koala-framework,kaufmo/koala-framework,kaufmo/koala-framework,yacon/koala-framework,koala-framework/koala-framework,Ben-Ho/koala-framework,nsams/koala-framework,nsams/koala-framework,Ben-Ho/koala-framework,koala-framework/koala-framework,yacon/koala-framework,kaufmo/koala-framework,yacon/koala-framework