Add a koschei icon for apps.fp.o.

roles/apps-fp-o/files/apps.yaml

@@ -197,6 +197,7 @@ children:
                 issues, your assistance here would be much appreciated.
     -   name:   Koschei
         data:
+            icon:   koschei.png
             url:    https://apps.fedoraproject.org/koschei/
             user_url: https://apps.fedoraproject.org/koschei/user/{user}
             package_url: https://apps.fedoraproject.org/koschei/package/{package}