[gnome-builder] flatpak: switch to --socket=fallback-x11

[Christian Hergert <chergert src gnome org>]

commit 41579ec64de3c216f0ebcf52c83d19525999e064
Author: Christian Hergert <chergert redhat com>
Date:   Mon Mar 18 12:58:07 2019 -0700

    flatpak: switch to --socket=fallback-x11

 build-aux/flatpak/org.gnome.Builder.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/build-aux/flatpak/org.gnome.Builder.json b/build-aux/flatpak/org.gnome.Builder.json
index b713c3e52..86a63ff10 100644
--- a/build-aux/flatpak/org.gnome.Builder.json
+++ b/build-aux/flatpak/org.gnome.Builder.json
@@ -14,7 +14,7 @@
         "--talk-name=org.freedesktop.Flatpak",
         "--device=dri",
         "--share=ipc",
-        "--socket=x11",
+        "--socket=fallback-x11",
         "--socket=wayland",
         "--socket=ssh-auth",
         "--filesystem=home",