Fixed scalar return values from GridColumn slicing
Fixed scalar return values from GridColumn slicing

vascotenner/holoviews,ioam/holoviews,ioam/holoviews,basnijholt/holoviews,ioam/holoviews,vascotenner/holoviews,basnijholt/holoviews,vascotenner/holoviews,basnijholt/holoviews