Update copyright info for Windows executable and fix SPDX markers

src/versioninfo.rc.in

@@ -2,8 +2,8 @@
     versioninfo.rc.in
 
     This file is part of Kleopatra, the KDE keymanager
-    SPDX-FileCopyrightText: 2013 g 10 Code GmbH
-                  2018 Intevation GmbH
+    SPDX-FileCopyrightText: 2013 g10 Code GmbH
+    SPDX-FileCopyrightText: 2018 Intevation GmbH
 
     SPDX-License-Identifier: GPL-2.0-or-later
 */
@@ -29,7 +29,7 @@ BEGIN
             VALUE "FileDescription", "Kleopatra - GnuPG User Interface\0"
             VALUE "FileVersion", "@kleopatra_version_win@\0"
             VALUE "InternalName", "kleopatra\0"
-            VALUE "LegalCopyright", "Copyright 2010-2018 The Kleopatra developers\0"
+            VALUE "LegalCopyright", "Copyright 2010-2021 The Kleopatra developers\0"
             VALUE "LegalTrademarks", "\0"
             VALUE "OriginalFilename", "kleopatra.exe\0"
             VALUE "PrivateBuild", "\0"