replace ServerRegistration#unfurlSrv to DNSResolver class

lib/database.js

@@ -1,5 +1,7 @@
 const sqlite = require('sqlite3')
 
+const TimeTracker = require('./time')
+
 class Database {
   constructor (app) {
     this._app = app
@@ -16,7 +18,7 @@ class Database {
 
   loadGraphPoints (graphDuration, callback) {
     // Query recent pings
-    const endTime = new Date().getTime()
+    const endTime = TimeTracker.getEpochMillis()
     const startTime = endTime - graphDuration
 
     this.getRecentPings(startTime, endTime, pingData => {