Input: stop telling users to snail-mail Vojtech

I do not think Vojtech wants snail mail these days (and he mentioned that
nobody has ever sent him snail mail), and the address is not even valid
anymore, so let's remove snail-mail instructions from the sources.

Acked-by: Vojtech Pavlik <vojtech@suse.cz>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>