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

[Richard Hughes <rhughes src gnome org>]

commit ecf415fd7723fd08ee56f7d2fe6af0ba02b8a216
Author: Richard Hughes <richard hughsie com>
Date:   Mon Mar 28 16:18:48 2016 +0100

    AppData: Mark as unremovable in GNOME Software

 src/org.gnome.Screenshot.appdata.xml.in |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/src/org.gnome.Screenshot.appdata.xml.in b/src/org.gnome.Screenshot.appdata.xml.in
index 7e9e52b..a357e22 100644
--- a/src/org.gnome.Screenshot.appdata.xml.in
+++ b/src/org.gnome.Screenshot.appdata.xml.in
@@ -32,5 +32,6 @@
   </kudos>
   <updatecontact>richard hughsie com</updatecontact>
   <project_group>GNOME</project_group>
+  <compulsory_for_desktop>GNOME</compulsory_for_desktop>
   <translation type="gettext">gnome-screenshot</translation>
 </application>