[gtkada] Minor tweak for in-line documentation:

[Emmanuel Briot]

Bobby D. Bryant writes:
 > I have not had a chance to look at 1.2.11, so ignore me if you've
 > already fixed it.

Thanks for the patch in the documentation. We have now fixed that in the
development version of GtkAda. It is very helpful to get comments on this
documentation. Given its size (around 450 pages), it is a very hard job to
proof read, so don't hesitate to send comments.

Emmanuel