[gitg] appdata: add project group tag

[Ignacio Casal Quinteiro <icq src gnome org>]

commit 5ccd4b11fb91aa4ce40fac6379d19013b87748af
Author: Ignacio Casal Quinteiro <icq gnome org>
Date:   Mon Jan 25 14:14:16 2016 +0100

    appdata: add project group tag

 data/gitg.appdata.xml |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/data/gitg.appdata.xml b/data/gitg.appdata.xml
index e92f63c..85a5a00 100644
--- a/data/gitg.appdata.xml
+++ b/data/gitg.appdata.xml
@@ -3,6 +3,7 @@
   <id type="desktop">gitg.desktop</id>
   <metadata_license>CC0</metadata_license>
   <project_license>GPL-2.0+</project_license>
+  <project_group>GNOME</project_group>
   <description>
     <p>
       gitg is a graphical user interface for git. It aims at being a small,