[gnome-software/1649-support-appstream-merging] Flatpak manifest: Specify 'main' branch for flatpak.git

[Milan Crha <mcrha src gnome org>]

commit a73935cbdb39f2ed0f2d9c349752fb74088ee651
Author: Milan Crha <mcrha redhat com>
Date:   Thu Mar 31 15:45:50 2022 +0200

    Flatpak manifest: Specify 'main' branch for flatpak.git
    
    The Flatpak project does not use 'master' branch anymore, thus explicitly
    specify the 'main' branch, to be able to build the Flatpak bundle.

 contrib/org.gnome.SoftwareDevel.json | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/contrib/org.gnome.SoftwareDevel.json b/contrib/org.gnome.SoftwareDevel.json
index be4a5340c..2e80db92a 100644
--- a/contrib/org.gnome.SoftwareDevel.json
+++ b/contrib/org.gnome.SoftwareDevel.json
@@ -179,7 +179,8 @@
             "sources": [
                 {
                     "type": "git",
-                    "url": "https://github.com/flatpak/flatpak.git";
+                    "url": "https://github.com/flatpak/flatpak.git";,
+                    "branch": "main"
                 }
             ]
         },