refactor(dashboard): adjust device sequencing

src/views/dashboard/Dashboard.vue

@@ -200,10 +200,10 @@ export default {
       })
     },
     sort (a, b) {
-      if (a.onlineStatus === 1) {
-        return -1
+      if (a.onlineStatus === b.onlineStatus) {
+        return a.createTime <= b.createTime ? 1 : -1
       }
-      return b.onlineStatus === 1 ? 1 : -1
+      return a.onlineStatus === 1 ? -1 : 1
     },
     getDevices (total) {
       if (!total || total === '-') {