[gnome-games] flatpak: Pin mednafen-pce-fast commit

[Alexander Mikhaylenko <alexm src gnome org>]

commit 0f7b58670cb150ebf6aa090663437588071b8b43
Author: Alexander Mikhaylenko <alexm gnome org>
Date:   Mon Jan 20 21:50:14 2020 +0500

    flatpak: Pin mednafen-pce-fast commit
    
    https://github.com/libretro/beetle-pce-fast-libretro/commit/7bf684982af264b4ed44c9ab9e64de7747df11e4
    broke gamepad input, as it expects the device to only have joypad capability,
    and rejects our joypad+analog device. Pin it to the previous commit until
    it's fixed.

 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 2bbaf6c9..c0fdb9d3 100644
--- a/flatpak/libretro-cores/libretro-mednafen_pce_fast.json
+++ b/flatpak/libretro-cores/libretro-mednafen_pce_fast.json
@@ -17,7 +17,8 @@
             "sources": [
                 {
                     "type": "git",
-                    "url": "https://github.com/libretro/beetle-pce-fast-libretro";
+                    "url": "https://github.com/libretro/beetle-pce-fast-libretro";,
+                    "commit": "408cc2cea4e0910ed0c34040ab0e13d06dd1fe75"
                 },
                 {
                     "type": "file",