This shortcut is not used by anything else. Searched on lxr, found one conflict in DigiKam, and the developers agreed to change it: https://bugs.kde.org/show_bug.cgi?id=386335
Tested in KDE Neon. Tried out Plasma, KWin, Dolphin, Kate, Konsole, Gwenview, Okular, Konversation, KTorrent, and Skanlite; all now have a consistent keyboard shortcut for their "Configure <Program>" menu items.