My bad: the feature is now working (with CTRL key and of course not
"any" key). I was using sudo dconf-editor to set the key and of course I
was actually setting therefore the root user's desktop feature. Setting
true my user's key still wouldn't work but setting then "enable-
animations" true
AFAICT, my left CTRL key is working but I won't be able to enable this feature.
Actually looking at Thomas's screenshot I've noticed that the dconf setting
apparently has been moved from settings-daemon/mouse to desktop/interface, what
explains that I wouldn't found the key definition in the
