0.14.1

Fixed

• A scan could delete your whole library if the drive wasn't available.
  If a library folder couldn't be read — drive disconnected, still spinning
  up, drive letter changed — the scan found nothing there, and that empty
  result was saved over your library. Folders that can't be read are now
  skipped and the books already known under them are kept; if nothing is
  readable at all, the scan stops and tells you rather than emptying
  anything. A scan that finds no books at all when your library isn't empty
  is likewise refused.