[gnome-boxes/build-gtk-vnc-from-tarball] build, CI: Build gtk-vnc from source tarball

[Felipe Borges <felipeborges src gnome org>]

commit d67bcf570dbe9ab5c31dd55866d25f71fa0ab0de
Author: Felipe Borges <felipeborges gnome org>
Date:   Wed Jun 19 11:41:01 2019 +0200

    build, CI: Build gtk-vnc from source tarball
    
    The git build could include build macros that are useful to catch
    warnings (-Werror) during development, but don't make much sense
    in clients of the library.

 build-aux/flatpak/org.gnome.Boxes.json | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)
---
diff --git a/build-aux/flatpak/org.gnome.Boxes.json b/build-aux/flatpak/org.gnome.Boxes.json
index 2a5dc181..8dce5b8c 100644
--- a/build-aux/flatpak/org.gnome.Boxes.json
+++ b/build-aux/flatpak/org.gnome.Boxes.json
@@ -73,10 +73,9 @@
             "name" : "gtk-vnc",
             "sources" : [
                 {
-                    "type" : "git",
-                    "url" : "https://gitlab.gnome.org/GNOME/gtk-vnc.git";,
-                    "tag" : "v0.9.0",
-                    "commit" : "8afbc55407c2625f9b1e64c53a0c0efd9939f6a8"
+                    "type" : "archive",
+                    "url" : "https://download.gnome.org/sources/gtk-vnc/0.9/gtk-vnc-0.9.0.tar.xz";,
+                    "sha256" : "3a9a88426809a5df2c14353cd9839b8c8163438cb708b31d8048c79d180fcab7"
                 }
             ]
         },