Log Message:
gallery-dl: Update to 1.15.2

Changes:
1.15.2
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### Additions
 - [pinterest] implement login support (#1055)
 - [reddit] add `date` metadata field (#1068)
 - [seiga] add metadata for single image downloads (#1063)
 - [twitter] support media from Cards (#937, #1005)
 - [weasyl] support api-key authentication (#1057)
 - add a `t` format string conversion for trimming whitespace (#1065)

### Fixes
 - [blogger] handle URLs with specified width/height (#1061)
 - [fallenangels] fix extraction of `.5` chapters
 - [gelbooru] rewrite mp4 video URLs (#1048)
 - [hitomi] fix image URLs and gallery URL pattern
 - [mangadex] unescape more metadata fields (#1066)
 - [mangahere] ensure download URLs have a scheme (#1070)
 - [mangakakalot] ignore "Go Home" buttons in chapter pages
 - [newgrounds] handle embeds without scheme (#1033)
 - [newgrounds] provide fallback URLs for video downloads (#1042)
 - [xhamster] fix user profile extraction