dyndns: run as a task

this lets us display logs

src/cron.js

@@ -245,8 +245,9 @@ function dynamicDnsChanged(enabled) {
 
     if (enabled) {
         gJobs.dynamicDns = new CronJob({
-            cronTime: '5 * * * * *',    // we only update the records if the ip has changed.
-            onTick: async () => await safe(dyndns.sync(AuditSource.CRON), { debug }),
+            // often home IPs change at the full hour, so we give it 5min to settle
+            cronTime: '00 5 * * * *',
+            onTick: async () => { await safe(dyndns.refreshDns(AuditSource.CRON), { debug }); },
             start: true
         });
     } else {