ox-koma-letter: Collapse space in copyright line

Match the space change made in Emacs's 19dcb237b5b (; Add 2022 to
copyright years, 2022-01-01) to avoid noise when syncing to the Emacs
repo.

lisp/ox-koma-letter.el

@@ -1,6 +1,6 @@
 ;;; ox-koma-letter.el --- KOMA Scrlttr2 Back-End for Org Export Engine  -*- lexical-binding: t; -*-
 
-;; Copyright (C) 2007-2022  Free Software Foundation, Inc.
+;; Copyright (C) 2007-2022 Free Software Foundation, Inc.
 
 ;; Author: Nicolas Goaziou <n.goaziou AT gmail DOT com>
 ;;         Alan Schmitt <alan.schmitt AT polytechnique DOT org>