Unbound: output statistics daily instead of just on shutdown

Unbound: output statistics daily instead of just on shutdown

Currently, Unbound only prints statistics if it is being shutdown
(mostly because of a machine reboot). This makes detecting DNS
anomalies hard as no intermediate statistic result is being logged.

This patch changes Unbound's behaviour in order to log statistics
every 86,400 seconds (i.e. 24 hours).

Signed-off-by: Peter Müller <peter.mueller@link38.eu>
Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>