Log Message:
gallery-dl: Update net/gallery-dl to 1.4.1

Changes:
1.4.1
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 - Added an ugoira post-processor to convert pixiv animations to WebM
 - Added --zip and --ugoira-conv command-line options
 - Changed how ugoira frame information is handled
    * instead of being written to a separate file, it is now made
      available as metadata field of the ZIP archive
 - Fixed manga and chapter titles for mangadex
 - Fixed file deletion by post-processors