message: fix a fatal... checksum bug
diff: @@ -86,11 +86,11 @@ Version.downloadVersionJar = async function (type: string, version: Version, min
  await DOWN(version.downloads[type].url, jar)
  if (checksum) {
  let hash = await CHECKSUM(jar)
  - if (hash != version.assetIndexDownloadInfo.sha1 && exist) {
  + if (hash != version.downloads[type].sha1 && exist) {
  await DOWN(version.downloads[type].url, jar)
  hash = await CHECKSUM(jar)
  }
  - if (hash != version.assetIndexDownloadInfo.sha1)
  + if (hash != version.downloads[type].sha1)
  throw new Error('SHA1 not matched! Probably caused by the incompleted file or illegal file source!')
  }
  return version
  @@ -158,7 +158,9 @@ async function downloadAsset(content: any, key: any, folder: any, assetsHost: an
  throw new Error(`SHA1 not matched!\n${sum}\n${hash}\n@${file}\n Probably caused by the incompleted file or illegal file source!`)
  }
  }
  -Version.downloadAssets = async function (version: Version, minecraft: MinecraftLocation, option?: { checksum?: boolean, assetsHost?: string }): Promise<Version> {
  +Version.downloadAssets = async function (version: Version, minecraft: MinecraftLocation, option?: {
  + checksum?: boolean, assetsHost?: string, cb?: (name: string, progress: number) => void
  +}): Promise<Version> {
  const folder: MinecraftFolder = typeof minecraft === 'string' ? new MinecraftFolder(minecraft) : minecraft
  let jsonPath = folder.getPath('assets', 'indexes', version.assets + '.json')
  if (!fs.existsSync(jsonPath)) {
  