Having the LED effects of the NumLock layer as a special LED mode has a number
of drawbacks, like not interacting well with led mode switching: one can't get
back to the NumLock effect once switching away from it (but the mode remains
active nevertheless).
To avoid this and other issues, don't make the effect a LED mode. Instead,
override the active LED mode with the numlock layer colors. This way, it is
always in sync with the layer.
Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>