[gtkada] Patch for Glade HScale/VScale top widget name generation

[Arnaud Charlet]

> Glade generates an incorrect name for the top-level widget for HScale
> and VScale controls.  It's a 1-line fix, and the patch follows:

Thanks for the patch.
Do you have a glade file showing the issue so that we can add it to our
test suite ?

Arno