[gnome-builder] build: pin flatpak/flatpak-builder to release tags

[Christian Hergert <chergert src gnome org>]

commit ba6d907f7de7e0b9bc08c5dc2d87f3b1f77a16f8
Author: Christian Hergert <chergert redhat com>
Date:   Fri Oct 25 09:12:46 2019 -0700

    build: pin flatpak/flatpak-builder to release tags

 build-aux/flatpak/org.gnome.Builder.json | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)
---
diff --git a/build-aux/flatpak/org.gnome.Builder.json b/build-aux/flatpak/org.gnome.Builder.json
index 25e623e71..57f41c82c 100644
--- a/build-aux/flatpak/org.gnome.Builder.json
+++ b/build-aux/flatpak/org.gnome.Builder.json
@@ -483,7 +483,8 @@
             "sources" : [
                 {
                     "type" : "git",
-                    "url" : "https://github.com/flatpak/flatpak.git";
+                    "url" : "https://github.com/flatpak/flatpak.git";,
+                    "branch" : "1.5.0"
                 }
             ]
         },
@@ -492,7 +493,8 @@
             "sources" : [
                 {
                     "type" : "git",
-                    "url" : "https://github.com/flatpak/flatpak-builder.git";
+                    "url" : "https://github.com/flatpak/flatpak-builder.git";,
+                    "branch" : "1.0.9"
                 }
             ]
         },