[ Sandro Knauß ]
* Bump Standards-Version to 4.5.1 (No changes needed).
* New upstream release (20.08.3).
* Update build-deps and deps with the info from cmake.
* Add kmailtransport-akonadi to Depends, as Exchange EWS resource
needs it to be able to send emails (Closes: #973567)
* Remove not existing version dependency from akonadi-server.
* Minimize the upstream GPG signing key.