[gnome-characters] AppData: Mark as unremovable in GNOME Software

[Richard Hughes <rhughes src gnome org>]

commit 906f447a0b497d8022ece2e6ff7f3041546da4c9
Author: Richard Hughes <richard hughsie com>
Date:   Mon Mar 28 16:27:02 2016 +0100

    AppData: Mark as unremovable in GNOME Software

 data/org.gnome.Characters.appdata.xml.in |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/data/org.gnome.Characters.appdata.xml.in b/data/org.gnome.Characters.appdata.xml.in
index 1f5b1c8..96c4b97 100644
--- a/data/org.gnome.Characters.appdata.xml.in
+++ b/data/org.gnome.Characters.appdata.xml.in
@@ -19,6 +19,7 @@
     </screenshot>
   </screenshots>
   <project_group>GNOME</project_group>
+  <compulsory_for_desktop>GNOME</compulsory_for_desktop>
   <url type="homepage">https://wiki.gnome.org/Design/Apps/CharacterMap</url>
   <url type="bugtracker">https://bugzilla.gnome.org/enter_bug.cgi?product=gnome-characters</url>
   <url type="donation">http://www.gnome.org/friends/</url>