monit: add PKG_LICENSE_FILES

Signed-off-by: Ian Leonard <antonlacon@gmail.com>
monit: Update to 5.9

Signed-off-by: Christoph König <christoph.koenig@gmail.com>
monit: update to 5.10

Run tested on ar71xx

Signed-off-by: Etienne CHAMPETIER <champetier.etienne@gmail.com>