Remove legacy Wine hack-around from rules rc.
Summary:
After we improved our StartupWMClass handling we worked with Wine
in https://bugs.winehq.org/show_bug.cgi?id=32699 to get them to add
StartupWMClass=foo.exe keys to the .desktop files they generate,
since they have foo.exe in WM_CLASS.
This old rule short-circuits the StartupWMClass handling prevented
this from actually working on our side.
BUG:393787
Reviewers: broulik, davidedmundson
Subscribers: plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D13058