set last_update broker_*_status

the broker status is usually called when the object changes, so lets update
the last_update attribute as well.
This addresses an issue where last_update does not get updated when a downtime ends.

src/naemon/broker.c

@@ -460,6 +460,7 @@ void broker_host_status(int type, int flags, int attr, host *hst)
 	ds.flags = flags;
 	ds.attr = attr;
 	get_broker_timestamp(&ds.timestamp);
+	hst->last_update = ds.timestamp.tv_sec;
 
 	ds.object_ptr = (void *)hst;
 
@@ -483,6 +484,7 @@ void broker_service_status(int type, int flags, int attr, service *svc)
 	ds.flags = flags;
 	ds.attr = attr;
 	get_broker_timestamp(&ds.timestamp);
+	svc->last_update = ds.timestamp.tv_sec;
 
 	ds.object_ptr = (void *)svc;