bug#43397: 28.0.50; Adding tool bar items: update tool bar

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Cc: 43397@debbugs.gnu.org,  Eli Zaretskii <eliz@gnu.org>,  Caio Henrique
>  <caiohcs0@gmail.com>
> Date: Tue, 03 May 2022 18:46:41 +0200
> 
> Lars Ingebrigtsen <larsi@gnus.org> writes:
> 
> > I added flushing in one of the interface functions -- I didn't know
> > whether any needed it, but they probably do.  
> 
> Now done -- seems to work fine.

Works here too, thanks.

I just hope we didn't make redisplay slower by flushing the tool bar
too frequently...