bug#46827: Broken initial size of GTK3 frame

[martin rudalics]

> 30. A lucid build gives me 31, so itʼs no better. (all emacs-27)

Here only GTK3 builds are affected.  Back then it took me months to get
these right.  So the values you report above are quite annoying.  Maybe
someone else could try ...

> <wild stab in the dark> What happens if you disable the code that
> displays text labels in the tool bar:

I thought about that too but it doesn't help.

martin