#18 Add dropbear support

[Jakob Albert]

Please add support for dropbear SSH.

Running dropbear as a server inside an Alpine LXC container on Proxmox, I can generate the log lines in the attached file.

Also see https://sourceforge.net/p/logwatch/mailman/message/37723669/

Thank you very much!

[Bjorn]

I believe the current dropbear script (in Logwatch 7.8-3) handles the dropbear SSH statements you posted.