[nautilus/gnome-3-28] Flatpak: specify branch

[Ernestas Kulik <ernestask src gnome org>]

commit caa1bcaa0361e36fe0611bcf95704b31c8e786d7
Author: Ernestas Kulik <ernestask gnome org>
Date:   Mon Mar 19 17:12:07 2018 +0200

    Flatpak: specify branch
    
    It defaults to being “master”, which doesn’t allow having multiple
    installations of different versions.

 build-aux/flatpak/org.gnome.Nautilus.json | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/build-aux/flatpak/org.gnome.Nautilus.json b/build-aux/flatpak/org.gnome.Nautilus.json
index c71a60124..f7197c126 100644
--- a/build-aux/flatpak/org.gnome.Nautilus.json
+++ b/build-aux/flatpak/org.gnome.Nautilus.json
@@ -1,5 +1,6 @@
 {
     "app-id": "org.gnome.NautilusStableFlatpak",
+    "branch": "3.28",
     "runtime": "org.gnome.Platform",
     "runtime-version": "3.28",
     "sdk": "org.gnome.Sdk",