Fix Ctrl+Del calling kill window - I need my Ctrl+Del in xemacs to delete a word forward :)

This appears to have been introduced by r568780, which turned META+CTRL+Del into CTRL+Del to "only use 3-modifiers shortcuts in the code"; it now uses the kde3 shortcut instead, ctrl+alt+esc, which should be okay since the point of r568780 was really to avoid META I think.