This affects all plugin authors: Caddy’s repo has moved from https://github.com/mholt/caddy to GitHub - caddyserver/caddy: Fast, multi-platform web server with automatic HTTPS.
This unexpectedly broke all builds with plugins, but I’ve patched the build server to work around that in the meantime. Still, plugin authors need to update import paths accordingly. I’ve filed issues on all registered plugins, I think, so most of the plugin authors should be aware.
Otherwise, there’s nothing really to do except update your bookmarks and links.