calendar: increased the dropdown window slightly of Calendar Combobox
calendar: increased the dropdown window slightly of Calendar Combobox

just to make double sure no accidental scrolling occurs in calendar grid.

wkitty42/fpGUI,wkitty42/fpGUI,wkitty42/fpGUI,wkitty42/fpGUI,wkitty42/fpGUI,wkitty42/fpGUI