There is no property setting that will do this. But you can try handling PrepareViewStyleInfo and do something there.
private void gridControl1_PrepareViewStyleInfo(object sender, GridPrepareViewStyleInfoEventArgs e)
{
GridCurrentCell cc = this.gridControl1.CurrentCell;
if(e.Style.CellType == "MaskEdit" && (e.RowIndex != cc.RowIndex || e.ColIndex != cc.ColIndex))
{
e.Style.MaskEdit.Mask = "";
}
}