Release v1.2.3

Release v1.2.2

v1.2.1

- MaxThumbnailSize is now configurable using the `max-thumbnail-size` config value. (#195)
- Twitch clips under `www.twitch.tv` domain work again. (#189)
- Imgur thumbnails are now proxied as well. (#187)
- Added link preview support for 7tv emote links. (#155)
- Skip lilliput if image is below maxThumbnailSize. (#184)
- Dev: Change Emote Set backend from `twitchemotes.com` to the Twitch Helix API. (#175, #188)