Issue: Only load broker config files based on extension

[3v1n0]

Is there an existing issue for this?

• I have searched the existing issues and found none that matched mine

Describe the issue

We just load any file that is in /etc/authd/brokers.d/ but this could be a problem when dpkg updates may lead files in that files (e.g. *.dpkg-old ones), so it's safer to just load files *.conf.

Steps to reproduce it

.

Ubuntu users: System information and logs

No response

Non Ubuntu users: System information and logs

No response

Relevant information

No response

Double check your logs

• I have redacted any sensitive information from the logs

[didrocks]

This is now fixed and merged.