Lua's json.encode produces {} for empty tables instead of [].
Use json.util.InitArray to mark tables as arrays so they encode
correctly as [] for authors, bookmarks, highlights, notes, and books.
pcall wraps socket.http.request returns as:
true, 1, status_code, headers, status_line
The old code captured '1' as the status code instead of
the actual HTTP status. Added '_' to skip the first return.