[aisleriot] appdata: Use correct metainfo namespace

[David King <davidk src gnome org>]

commit 4f4b042617b6fcdacfe296db82d0b3506be2d329
Author: David King <amigadave amigadave com>
Date:   Thu Aug 26 15:32:52 2021 +0100

    appdata: Use correct metainfo namespace
    
    https://www.freedesktop.org/software/appstream/docs/chap-Metadata.html
    
    Related: https://gitlab.gnome.org/GNOME/aisleriot/-/issues/45

 data/sol.metainfo.xml.in | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
---
diff --git a/data/sol.metainfo.xml.in b/data/sol.metainfo.xml.in
index eac0c89f..a502c2b9 100644
--- a/data/sol.metainfo.xml.in
+++ b/data/sol.metainfo.xml.in
@@ -27,9 +27,8 @@
   of the GNU Free Documentation License along with this program.
   If not, see <https://www.gnu.org/licenses/>.
 -->
-<!-- FIXME: the xmlns for appdata is made-up -->
 <component
-  xmlns="https://www.freedesktop.org/standards/appdata/1.0";
+  xmlns="https://specifications.freedesktop.org/metainfo/1.0";
   type="desktop">
   <id>sol.desktop</id>
   <metadata_license>GPL-3.0+ or GFDL-1.3-only</metadata_license>