Added missing default monitor interval.

server/core/monitor.c

@@ -85,6 +85,7 @@ MONITOR	*mon;
 	mon->read_timeout = DEFAULT_READ_TIMEOUT;
 	mon->write_timeout = DEFAULT_WRITE_TIMEOUT;
 	mon->connect_timeout = DEFAULT_CONNECT_TIMEOUT;
+	mon->interval = MONITOR_INTERVAL;
 	spinlock_init(&mon->lock);
 	spinlock_acquire(&monLock);
 	mon->next = allMonitors;