COPYING: fix a typo in a preamble

Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>

COPYING

-This software is licenced under the GNU GENERAL PUBLIC LICENCE Version
+This software is licensed under the GNU GENERAL PUBLIC LICENCE Version
 2. Except that any software in the lib/ directory is for the creation of a
 linkable library to the tools and is licensed under the GNU LESSER GENERAL
 PUBLIC LICENCE Version 2.1.  Contributing Authors agree that their code is