Zulip

This release is primarily intended to improve the experience for new Zulip installations; it has minimal changes for existing servers.

• Added support for getting multi-domain certificates with setup-certbot.
• Improved various installer error messages and sections of the installation documentation to help avoid for common mistakes.
• The Google auth integration now always offers an account chooser.
• Fixed buggy handling of avatars in Slack import.
• Fixed nginx configuration for mobile API authentication to access uploads.
• Updated translation data, including significant new Italian strings.