Consistently call commands 'Befehle' in German help
Consistently call commands 'Befehle' in German help

Previously, the output of `--help` mixed the two German terms 'Befehl'
and 'Kommando' in the very same line. So consistently use just one of
them. The winner is used already in some other messages regarding
command execution.

der-lyse/newsboat,der-lyse/newsboat,newsboat/newsboat,newsboat/newsboat,newsboat/newsboat,newsboat/newsboat,newsboat/newsboat,der-lyse/newsboat,newsboat/newsboat,newsboat/newsboat,der-lyse/newsboat,der-lyse/newsboat,der-lyse/newsboat,newsboat/newsboat,der-lyse/newsboat,der-lyse/newsboat