fix: 修复 eslint 报错

lib/plugins/mailchimp.js

@@ -1,15 +1,19 @@
 import BLOG from '@/blog.config'
 
 /**
-* 订阅邮件-服务端接口
-* @param {*} email
-* @returns
-*/
-export default function subscribeToMailchimpApi({ email, first_name = '', last_name = '' }) {
+ * 订阅邮件-服务端接口
+ * @param {*} email
+ * @returns
+ */
+export default function subscribeToMailchimpApi({
+  email,
+  first_name = '',
+  last_name = ''
+}) {
   const listId = BLOG.MAILCHIMP_LIST_ID // 替换为你的邮件列表 ID
   const apiKey = BLOG.MAILCHIMP_API_KEY // 替换为你的 API KEY
   if (!email || !listId || !apiKey) {
-    return {}
+    return Promise.resolve({})
   }
   const data = {
     email_address: email,