Remove Dovel (source code link is down)

- ref. https://github.com/awesome-selfhosted/awesome-selfhosted/issues/3558
- `https://blmayer.dev/x/dovel : HTTP 500` or `(52) Empty reply from server`

README.md

@@ -396,7 +396,6 @@ Simple deployment of [E-mail](https://en.wikipedia.org/wiki/Email) servers, e.g.
 - [AnonAddy](https://anonaddy.com) - Open source email forwarding service for creating aliases. ([Source Code](https://github.com/anonaddy/anonaddy)) `MIT` `PHP`
 - [DebOps](https://docs.debops.org/) - Your Debian-based data center in a box. A set of general-purpose Ansible roles that can be used to manage Debian or Ubuntu hosts. ([Source Code](https://github.com/debops/debops)) `GPL-3.0` `YAML/Ansible/Python`
 - [docker-mailserver](https://docker-mailserver.github.io/docker-mailserver/edge/) - Production-ready fullstack but simple mail server (SMTP, IMAP, LDAP, Antispam, Antivirus, etc.) running inside a container. Only configuration files, no SQL database. ([Source Code](https://github.com/docker-mailserver/docker-mailserver)) `MIT` `Docker`
-- [Dovel](https://dovel.email) - SMTP server that sends and receives emails according to a simple configuration file, with an optional web interface that you can use to browse your emails. ([Source Code](https://blmayer.dev/x/dovel)) `LGPL-3.0` `Go`
 - [emailwiz](https://github.com/LukeSmithxyz/emailwiz) - Luke Smith's bash script to completely automate the setup of a Postfix/Dovecot/SpamAssassin/OpenDKIM server on debian. `GPL-3.0` `Bash`
 - [homebox](https://github.com/progmaticltd/homebox) - Suite of Ansible scripts to deploy a fully functional mail server on Debian. Unobtrusive and automatic as much as possible, focusing on stability and security. `GPL-3.0` `Shell`
 - [Inboxen](https://inboxen.org) - Inboxen is a service that provides you with an infinite number of unique inboxes. ([Source Code](https://github.com/Inboxen/Inboxen)) `GPL-3.0` `Python`