bug#55970: 29.0.50; Emacs crashes when dragging the scroll bar with "--with-pgtk" and "--without-toolkit-scroll-bars" configure flags

[Eli Zaretskii]

> From: समीर सिंह Sameer Singh <lumarzeli30@gmail.com>
> Date: Wed, 15 Jun 2022 00:14:45 +0530
> Cc: 55970@debbugs.gnu.org
> 
> It does not crash now!

Thanks for testing, I will let it to Po Lu to decide whether that's
the proper fix in this case.