Log Message:
snac: update to 2.57. Changes:

Added support for listening on UNIX-like sockets.

Don't allow empty polls.

Added support for Markdown-style images (converted to attachments) and
strikethrough text.

Added support for incoming `Move` messages: when received, the new
account is followed and the old one is unfollowed.

Incoming `EmojiReact` messages are internally converted to `Like` (more
proper support will happen eventually).

Blocks are also notified.

Mastodon API: fixed a cache bug when following local users.