loki-setup: use xdg-desktop-menu instead of loki-setup legacy menu entries

misc/setup/preuninstall.sh

@@ -1,2 +1,10 @@
 #!/bin/sh
 rmdir --ignore-fail-on-non-empty demoq3 missionpack >& /dev/null
+if test -e "$SETUP_INSTALLPATH"/ioquake3.desktop.in; then
+  xdg_desktop_menu=`which xdg-desktop-menu 2>/dev/null`
+  if test "x$xdg_desktop_menu" = x; then
+    xdg_desktop_menu=./xdg-desktop-menu
+  fi
+  $xdg_desktop_menu uninstall --novendor ioquake3.desktop
+  rm ioquake3.desktop
+fi