make sure to use the same file name when replicating a desktop file

when replicating an existing desktop file also use the exactly same
entry name to enable users to override a global autostart (e.g. from
a distro)

previously the translated name was used.

(user visible names etc. remain working as expected, so are desktop files
replicated before this change)

https://bugs.launchpad.net/ubuntu/+source/kde-workspace/+bug/923360