Adhere to coding style guidelines.
See https://invent.kde.org/pim/kleopatra/-/merge_requests/16#note_428716,
https://invent.kde.org/pim/kleopatra/-/merge_requests/16#note_428717,
https://invent.kde.org/pim/kleopatra/-/merge_requests/16#note_428718 and
https://invent.kde.org/pim/kleopatra/-/merge_requests/16#note_428721.
Dropped dummy log entry in favor of Q_UNUSED(), see
https://invent.kde.org/pim/kleopatra/-/merge_requests/16#note_428720.