buildroot

package/monit: security bump to version 5.20.0

Fixes CVE-2016-7067.

Note that since version 5.20.0 monit optionally depends on zlib.

Signed-off-by: Jörg Krause <joerg.krause@embedded.rocks>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>