[gnome-music/wip/jfelder/use-tracker-2.3] flatpak: Use tracker 2.3 version

[Jean Felder <jfelder src gnome org>]

commit cf3d4ff7dd38fb2f33f8cb40c7813d952ebaba9c
Author: Jean Felder <jfelder src gnome org>
Date:   Tue Sep 24 02:12:02 2019 +0200

    flatpak: Use tracker 2.3 version
    
    The next release of Tracker will be a backwards-incompatible 3.0
    release. Work for Tracker 3.0 has already begun in the master
    branch. Use the the tracker-2.3 branch to keep stability.
    
    See:
    https://discourse.gnome.org/t/tracker-has-branched-for-3-0-use-the-2-3-branch-if-you-want-stability/1889

 org.gnome.Music.json | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/org.gnome.Music.json b/org.gnome.Music.json
index ebfdf477..2d72c9ec 100644
--- a/org.gnome.Music.json
+++ b/org.gnome.Music.json
@@ -70,7 +70,8 @@
             "sources": [
                 {
                     "type": "git",
-                    "url": "https://gitlab.gnome.org/GNOME/tracker.git";
+                    "url": "https://gitlab.gnome.org/GNOME/tracker.git";,
+                    "branch": "tracker-2.3"
                 }
             ]
         },