Fix launch kscreen kcm in font kcm.

.desktop won't work and will give an error in kcmshell


(cherry picked from commit aa295bd3)

kcms/fonts/package/contents/ui/main.qml

@@ -25,7 +25,7 @@ KCM.SimpleKCM {
         visible: KCMShell.authorize("kcm_kscreen.desktop").length > 0
         text: i18n("Change Display Scaling…")
         iconName: "preferences-desktop-display"
-        onTriggered: KCMShell.open("kcm_kscreen.desktop")
+        onTriggered: KCMShell.open("kcm_kscreen")
     }
 
     ColumnLayout {