axios 上传文件出现 the request was rejected because no multipart boundary was found

已解决，参考 https://www.cnblogs.com/czy960731/p/11105166.html

axios config 添加 transformRequest

let config = {
    headers: {
      'Content-Type': 'multipart/form-data'
    },
    transformRequest: [function (data) {
      return data
    }]
  }