Drop X-KDE-Keywords entries from kcm desktop files
Current KCM dialogs (as used in Kontact and KOrganizer) do not make use of that property, also has KCMUtils been broken when it comes to reading the localized variants of the data as well as reading the list as a list in JSON format
I propose to also backport that change to release/21.08 branch, no need to keep translators busy there.
Edited by Friedrich W. H. Kossebau