海报：修复海报保存报错

sheep/components/s-share-modal/canvas-poster/poster/index.js

@@ -1,6 +1,7 @@
 import user from './user';
 import goods from './goods';
 import groupon from './groupon';
+import third from '@/sheep/api/migration/third';
 
 export function getPosterData(options) {
   switch (options.shareInfo.poster.type) {
@@ -30,3 +31,9 @@ export function formatImageUrlProtocol(url) {
 
   return url;
 }
+
+// 获得微信小程序码 （Base64 image）
+export async function getWxaQrcode(path, query) {
+  const res = await third.wechat.getWxacode(path, query);
+  return 'data:image/png;base64,' + res.data;
+}