[gnome-games] flatpak: Pin down beetle-pce-fast commit

[Alexander Mikhaylenko <alexm src gnome org>]

commit 1df65316d7654529f125320c1384baedac2f209e
Author: Alexander Mikhaylenko <alexm gnome org>
Date:   Sun May 24 00:10:00 2020 +0500

    flatpak: Pin down beetle-pce-fast commit
    
    See https://github.com/libretro/beetle-pce-fast-libretro/issues/155

 flatpak/libretro-cores/libretro-mednafen_pce_fast.json | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/flatpak/libretro-cores/libretro-mednafen_pce_fast.json 
b/flatpak/libretro-cores/libretro-mednafen_pce_fast.json
index 614dca67..a487037d 100644
--- a/flatpak/libretro-cores/libretro-mednafen_pce_fast.json
+++ b/flatpak/libretro-cores/libretro-mednafen_pce_fast.json
@@ -16,7 +16,8 @@
             "sources": [
                 {
                     "type": "git",
-                    "url": "https://github.com/libretro/beetle-pce-fast-libretro";
+                    "url": "https://github.com/libretro/beetle-pce-fast-libretro";,
+                    "commit": "a53610b2e545f0ba2b0fac6bdc410a51d41a0f17"
                 },
                 {
                     "type": "file",