Deselects the pop-up list item at the specified index if it’s selected.
Original signature is '- (void)deselectItemAtIndex:(NSInteger)index'
Available in Mac OS X v10.0 and later.


- index (NSInteger)
- The index of the item to deselect.

- Available in Monobjc Bridge: 10.6 (For Mac OS X 10.6 and later), 10.5 (For Mac OS X 10.5 and later)