package/s6-linux-utils: bump version to 2.5.1.0
The hash of the COPYING file is updated to take into account the
copyright year change:
-Copyright (c) 2011-2018 Laurent Bercot <ska-skaware@skarnet.org>
+Copyright (c) 2011-2019 Laurent Bercot <ska-skaware@skarnet.org>
Signed-off-by: Eric Le Bihan <eric.le.bihan.dev@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>