[gnome-builder] flatpak: fix channel name for nightly

[Christian Hergert <chergert src gnome org>]

commit d2641da0eaff461a0f35ad34732ccc35df3ee964
Author: Christian Hergert <chergert redhat com>
Date:   Wed Feb 20 12:19:22 2019 -0800

    flatpak: fix channel name for nightly

 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 2017f36f5..eeeaa10c0 100644
--- a/build-aux/flatpak/org.gnome.Builder.json
+++ b/build-aux/flatpak/org.gnome.Builder.json
@@ -556,7 +556,7 @@
                 "-Dpython_libprefix=python3.7",
                 "-Denable_tracing=false",
                 "-Dwith_help=true",
-                "-Dwith_channel=flatpak-beta",
+                "-Dwith_channel=flatpak-nightly",
                 "-Dwith_deviced=true"
             ],
             "cleanup" : [