Fix being unable to set the right permissions for kde_settings.conf
If we are creating a config file and its directory doesn't exist, we fail to set the right permissions for the file.
This affects kde_settings.conf and results in the KCM not being able to read stored settings.
save settings in the kcm in various ways
kde_settings.conf is now world readable agian
Subscribers: plasma-devel, ngraham
Differential Revision: https://phabricator.kde.org/D27388