Fixed bug in GridPlot._format_title
Fixed bug in GridPlot._format_title

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