change code from roListScreen to roGridScreen

change code from roListScreen to roGridScreen

        ' for roListScreen
        screen = CreateObject("roListScreen")
        ' use certs to allow for https thumbnails
        screen.SetCertificatesFile("common:/certs/ca-bundle.crt")
        'screen.SetCertificatesDepth(10)
        screen.InitClientCertificates()
        screen.SetMessagePort(CreateObject("roMessagePort"))
        screen.SetContent(contentList)