Breaking changes for MQTT go-ACL users

Hello,

I just noticed that a recent update to the v3 docker container also updated the database with the new format for usernames and emails. This update had the unintended effect to break the ACL check in the go-acl-plugin for mosquitto.

Running the ACL with a custom config file in my server environment right now and new connections can not be accepted. I guess that this is because the queries for users is not updated to include the rename from “username” to “email” in postgres.

As I tried to update the config file I once again looked at the documentation for the ACL plugin and it has not been updated for the new database structure. I managed to make it work by trial and error but I think the document should be updated as well.

It might be a good idea to update the changelog with a notice that the update breaks the ACL plugin so that custom configurations can be updated.

Thanks for a great product!

Would you mind creating a pull request with the changes that you needed to make? All documentation source can be found in: https://github.com/brocaar/chirpstack-docs

I have now made a PR for the changes to the docs and added a notice in the changelog that the ACL breaks.