[STUMP] Window Manager does not support MWM hints

Depending how I am launching the feh image viewer, I get following
error:

feh WARNING: Window Manager does not support MWM hints. To get a
borderless window I have to bypass your wm.

This is happening, when I try to press "q" in feh, to quit the
viewer. Sometimes it works, sometimes not in stumpwm, while in other
window managers it works always.

Jean Louis