[gnome-music/wip/mschraal/file-exists-async] flatpak: Use grilo-plugins fix

[Marinus Schraal <mschraal src gnome org>]

commit e3d48826bfdd7b380dd1687ec85fb3fc693833c5
Author: Marinus Schraal <mschraal gnome org>
Date:   Tue Aug 17 14:40:04 2021 +0200

    flatpak: Use grilo-plugins fix
    
    Use the wip/mschraal/tracker3-resolve-async branch. Without this fix the
    experience is suboptimal at best.
    
    Related: grilo-plugins!117

 org.gnome.Music.json | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/org.gnome.Music.json b/org.gnome.Music.json
index b4981c30e..5ce87b95a 100644
--- a/org.gnome.Music.json
+++ b/org.gnome.Music.json
@@ -109,6 +109,7 @@
         },
         {
             "name": "grilo-plugins",
+            "branch": "wip/mschraal/tracker3-reolve-async",
             "buildsystem": "meson",
             "config-opts": [ "-Denable-bookmarks=no",
                              "-Denable-dleyna=no",