[CM] snd 19.7 gtk-effects menu not working

[bil at ccrma.Stanford.EDU]

The gtk version of Snd is caught in-between versions.
I thought gtk 4 was "right around the corner" years
ago and started trying to port everything to it.
Since the changes between version 3 and 4 are enormous,
and (it turned out) gtk 4 really isn't ready yet,
I got trapped.  Snd itself works (though I am not
happy with it) in gtk 2/3 but does not work in 4,
and the *.scm files are not in any consistent version.
I use motif which is still (thank goodness) available
from debian and fedora.  I suppose I could return to
the gtk3 scheme files.  The real problem is that I
think the gtk interface is ugly, so it's hard to
get up the energy to work on it.