[empathy] Add a missing tag to the AppData file

[Richard Hughes <rhughes src gnome org>]

commit fb99c0b4a4093a3b5dc4a65005783105a299e115
Author: Richard Hughes <richard hughsie com>
Date:   Mon Jan 25 13:10:11 2016 +0000

    Add a missing tag to the AppData file

 data/empathy.appdata.xml.in |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/data/empathy.appdata.xml.in b/data/empathy.appdata.xml.in
index 0d655f4..f23a15b 100644
--- a/data/empathy.appdata.xml.in
+++ b/data/empathy.appdata.xml.in
@@ -15,4 +15,5 @@
     <screenshot 
type="default">https://wiki.gnome.org/Empathy?action=AttachFile&amp;do=get&amp;target=empathy.png</screenshot>
   </screenshots>
   <updatecontact>telepathy lists freedesktop org</updatecontact>
+  <project_group>GNOME</project_group>
 </application>