fix web bugs

easytier-web/frontend/src/components/DeviceList.vue

@@ -27,7 +27,7 @@ const loadDevices = async () => {
             public_ip: device.client_url,
             running_network_instances: device.info?.running_network_instances.map((instance: any) => Utils.UuidToStr(instance)),
             running_network_count: device.info?.running_network_instances.length,
-            report_time: device.info?.report_time,
+            report_time: new Date(device.info?.report_time).toLocaleString(),
             easytier_version: device.info?.easytier_version,
             machine_id: Utils.UuidToStr(device.info?.machine_id),
         });

easytier-web/frontend/src/components/DeviceManagement.vue

@@ -210,9 +210,20 @@ const loadDeviceInfo = async () => {
 }
 
 const exportConfig = async () => {
+  if (!deviceId.value || !instanceId.value) {
+    toast.add({ severity: 'error', summary: 'Error', detail: 'No network instance selected', life: 2000 });
+    return;
+  }
+
+  try {
     let ret = await props.api?.get_network_config(deviceId.value, instanceId.value);
     delete ret.instance_id;
     exportJsonFile(JSON.stringify(ret, null, 2),instanceId.value +'.json');
+  } catch (e: any) {
+    console.error(e);
+    toast.add({ severity: 'error', summary: 'Error', detail: 'Failed to export network config, error: ' + JSON.stringify(e.response.data), life: 2000 });
+    return;
+  }
 }
 
 const importConfig = () => {
@@ -316,9 +327,9 @@ onUnmounted(() => {
         <Status v-bind:cur-network-inst="curNetworkInfo" v-if="needShowNetworkStatus">
         </Status>
         <Divider />
-        <center>
+        <div class="text-center">
           <Button @click="updateNetworkState(true)" label="Disable Network" severity="warn" />
-        </center>
+        </div>
     </div>
 
     <!-- For disabled network, show the config -->