fix: full text error in discuz (#3880)

lib/routes/discuz/discuz.js

@@ -25,11 +25,14 @@ async function load(baseUrl, itemLink, ctx, charset) {
     // 处理编码问题
     let responseData;
     if (charset === 'utf-8') {
-        responseData = await got.get(itemLink).data;
+        responseData = (await got.get(itemLink)).data;
     } else {
         responseData = iconv.decode((await got.get({ url: itemLink, responseType: 'buffer' })).data, charset);
     }
-
+    if (!responseData) {
+        const description = '获取详细内容失败';
+        return { description };
+    }
     const $ = cheerio.load(responseData);
     // 只抓取论坛1楼消息
     const description = $('div#postlist div[id^=post] td[id^=postmessage]')