refactor: Maybe the categories is fine since it's user who makes it usually, and updating library doesn't affect it.

Signed-off-by: KaiserBh <kaiserbh@proton.me>

data/src/main/sqldelight/tachiyomi/data/mangas_categories.sq

@@ -20,7 +20,7 @@ END;
 
 insert:
 INSERT INTO mangas_categories(manga_id, category_id, last_modified_at)
-VALUES (:mangaId, :categoryId, 0);
+VALUES (:mangaId, :categoryId, strftime('%s', 'now'));
 
 deleteMangaCategoryByMangaId:
 DELETE FROM mangas_categories