[Users] Scrolling the message list is very slow on a raspberry pi5

[David Laight]

Scrolling the message list (using the 'up' and 'down' icons on the scroll bar)
is very slow on my (new) raspberry pi.
It was fine on a much older x86-64 Ubuntu system.

I suspect it is more of a gtk or 'mouse repeat rate' issue, but perhaps easier
to fix/avoid in claws.

It isn't a cpu problem, the usage is fairly high but scales with the height
of the message list window.

The scrolling is 'very smooth', so I actually suspect each mouse 'event' (from
holding the left button down) is only moving the window by one pixel row.
So manages to scroll (about) 2 msg/sec - and the eye can scan the subject lines
much faster than that.

OTOH if I click on the scroll bar (to page up/down) it seems to do a fast
'smooth scroll' - but that is hard to do consistently especially at the top
of the mailbox (and I don't think there is a keyboard shortcut for it).

Similarly the 'n' keyboard shortcut 'rattles' through the messages.

This is all a problem because I'm trying to quickly scan the subject lines
from the linux kernel mailing list (getting on for 2k messages/day).

	David