fix: Update file is correct now

src/views/FileManagement/index.vue

@@ -273,7 +273,7 @@ const submitData = async (data: DataItem) => {
     });
     return false;
   }
-  if (data.file.length==0 && !!!form.value.id) {
+  if (data.file !== undefined && data.file.length == 0 && !!!form.value.id) {
     ElMessage({
       message: `请选择要上传的文件`,
       type: "error",