Log Message:
gallery-dl: Update to 1.15.3

Changes:
1.15.3
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### Additions
 - [sankakucomplex] extract videos and embeds (#308)
 - [twitter] add support for lists (#1096)
 - [postprocessor:metadata] accept string-lists for `content-format` (#1080)
 - implement `modules` and `extension-map` options

### Fixes
 - [500px] update query hashes
 - [8kun] fix file URLs of older posts (#1101)
 - [exhentai] update image URL parsing (#1094)
 - [hentaifoundry] update `YII_CSRF_TOKEN` cookie handling (#1083)
 - [hentaifoundry] use scheme from input URLs (#1095)
 - [mangoxo] fix metadata extraction
 - [paheal] fix extraction (#1088)
 - collect post processors from `basecategory` entries (#1084)