[totem] Add a missing tag to the AppData file

[Richard Hughes <rhughes src gnome org>]

commit b0f4c850a785e817474e4282f2d9599ab900af6b
Author: Richard Hughes <richard hughsie com>
Date:   Mon Jan 25 13:10:32 2016 +0000

    Add a missing tag to the AppData file

 data/appdata/org.gnome.Totem.appdata.xml.in |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/data/appdata/org.gnome.Totem.appdata.xml.in b/data/appdata/org.gnome.Totem.appdata.xml.in
index 594d776..8b21c57 100644
--- a/data/appdata/org.gnome.Totem.appdata.xml.in
+++ b/data/appdata/org.gnome.Totem.appdata.xml.in
@@ -30,4 +30,5 @@
   <screenshot width="1024" 
height="576">https://git.gnome.org/browse/totem/plain/data/appdata/ss-music-playlist.png</screenshot>
   </screenshots>
   <updatecontact>hadess hadess net</updatecontact>
+  <project_group>GNOME</project_group>
 </application>