message: update prefecth_files
diff: @@ -348,9 +348,7 @@ components:
  description: usually to be the metadata source
  type: string
  prefetch_files:
  - description: files that need to be prefetched
  - type: array
  - items:
  + description: local file path which recorded a file list to be prefetched
  type: string
  config:
  description: inline request, use to configure fs backend.
  