Hi Chris, Thanks for reporting this. This file is actually obsolete and was only needed when Diodon was only available on Launchpad before publishing it to Debian and synced to Ubuntu from there. See here [0] for more information.
This file should indeed be removed from the Debian package. Oliver [0] https://wiki.ubuntu.com/Apport/DeveloperHowTo#Applications_not_included_in_Ubuntu.27s_repositories_but_hosted_on_Launchpad
