[gucharmap] appdata: Add GFDL option

[Christian Persch <chpe src gnome org>]

commit cd62236c68bbe068d712ea8ac5a0db473de1c539
Author: Christian Persch <chpe src gnome org>
Date:   Mon Mar 5 13:42:28 2018 +0100

    appdata: Add GFDL option

 data/gucharmap.appdata.xml.in |   28 ++++++++++++++++++++--------
 1 files changed, 20 insertions(+), 8 deletions(-)
---
diff --git a/data/gucharmap.appdata.xml.in b/data/gucharmap.appdata.xml.in
index 451defc..255c3ac 100644
--- a/data/gucharmap.appdata.xml.in
+++ b/data/gucharmap.appdata.xml.in
@@ -3,24 +3,36 @@
   Copyright © 2014 Christian Persch
 
   This program is free software; you can redistribute it and/or modify
-  it under the terms of the GNU General Public License as published by
-  the Free Software Foundation; either version 3, or (at your option)
-  any later version.
+  it under the terms of either:
 
-  This program is distributed in the hope conf it will be useful,
+  * the GNU General Public License as published by the Free
+    Software Foundation; either version 3 of the License, or (at your
+    option) any later version.
+
+  or
+
+  * the GNU Free Documentation License version 1.3 as published by the
+    Free Software Foundation; with no Invariant Sections, no Front-Cover
+    Texts, and no Back-Cover Texts.
+
+  or both in parallel, as here.
+
+  This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
+  GNU General Public License and the GNU Free Documentation License
+  for more details.
 
-  You should have received a copy of the GNU General Public License
-  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+  You should have received a copy of the GNU General Public License and
+  of the GNU Free Documentation License along with this program.
+  If not, see <https://www.gnu.org/licenses/>.
 -->
 <component type="desktop-application"
   xmlns="https://specifications.freedesktop.org/metainfo/1.0";
   xmlns:xi="http://www.w3.org/2001/XInclude";
   xmlns:its="http://www.w3.org/2005/11/its";>
   <id>gucharmap.desktop</id>
-  <metadata_license>GPL-3.0+</metadata_license>
+  <metadata_license>GPL-3.0+ or GFDL-1.3-only</metadata_license>
   <project_license>GPL-3.0+</project_license>
   <_name>Character Map</_name>
   <_summary>Insert special characters into documents</_summary>