Partial fix for JWM blurry wallpaper

The problem was reported by SteveS:

https://forum.puppylinux.com/viewtopic.php?t=13561

I do get this blurry-wallpaper problem at shutdown, when a window asks whether you want to save the session. That happens because ROX-Filer has exited and fallback is to the wallpaper provided by JWM. I have fixed that, so I get nice JWM wallpaper at shutdown:

https://github.com/bkauler/woofq/commit/25282aa1c898c876652d59f3cd6ef2a5c31aacdf

I don't get the blurry wallpaper in icon-free-desktop mode, but that is because my screen is 1920x1080, and the wallaper is the same size. JWM doesn't have to scale it down, as in SteveS' case.

So, a partial fix, only at shutdown and when JWM doesn't have to scale the image down.

This is really a bug in JWM, and should be reported to Joe.    

Tags: easy