优化微信文件: 增加文件类型的过滤

src/pages/print/index.vue

@@ -382,6 +382,7 @@ function selectFile() {
       uni.chooseMessageFile({
         count: 10,
         type: "file",
+        extension: allowType,
         success (res) {
           console.log('chooseMessageFile FILE res: ', res);
           if (res.errMsg == "chooseMessageFile:ok") {