Bug#824965: diodon: Update to new upstream version 1.5.0

[Oliver Sauder]

Severity: important

Reverting severity to important as it has been marked by mistake (Diodon
doesn't use Qt).

Also a package updating to 1.5.0 is available
https://mentors.debian.net/package/diodon

Looking for a sponsor.

Regards,
Oliver