/usr/share/doc/plasma-wallpapers-addons/changelog.Debian.gz is in plasma-wallpapers-addons 4:4.13.0-0ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/plasma-wallpapers-addons/../plasma-dataengines-addons/changelog.Debian.gz