A small xml fix on default attitude indicator tooltip.

Since the default tooltip for attitude indicator is buggy, here is a small replacement code attached. Don't believe me? Try different pitch and bank attitudes and read the tooltip values in the Baron i.e. :) NOT what I'd call a serious bug, but annoying enough to deserve a fix.Ok, I'm aware that this is rather obvious for many, but some may have a use for it.Hope the attachment show up.