VPN连接状态默认‘未连接’

src/views/devinfo.vue

@@ -26,7 +26,7 @@
           </div>
           <div class="item">
             <span class="span1">VPN连接状态</span>
-            <span>{{ vpnstate }}</span>
+            <span>{{ vpnstate || '未连接' }}</span>
           </div>
         </div>
       </div>