[gnome-sdk-images] Add the sdk extension point

[Alexander Larsson <alexl src gnome org>]

commit 176954002e45e7aa65f768447487829ff9a326aa
Author: Alexander Larsson <alexl redhat com>
Date:   Fri Mar 17 15:31:33 2017 +0100

    Add the sdk extension point

 org.gnome.Sdk.json.in |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/org.gnome.Sdk.json.in b/org.gnome.Sdk.json.in
index e6cb58a..8c56d7a 100644
--- a/org.gnome.Sdk.json.in
+++ b/org.gnome.Sdk.json.in
@@ -24,6 +24,9 @@
         "--extension=org.freedesktop.Platform.GStreamer=directory=lib/extensions/gstreamer-1.0",
         "--extension=org.freedesktop.Platform.GStreamer=version=1.6",
         "--extension=org.freedesktop.Platform.GStreamer=subdirectories",
+        "--extension=org.freedesktop.Sdk.Extension=subdirectories",
+        "--extension=org.freedesktop.Sdk.Extension=directory=lib/sdk",
+        "--extension=org.freedesktop.Sdk.Extension=no-autodownload=true",
         "--env=GI_TYPELIB_PATH=/app/lib/girepository-1.0",
         
"--env=GST_PLUGIN_SYSTEM_PATH=/app/lib/gstreamer-1.0:/usr/lib/extensions/gstreamer-1.0:/usr/lib/gstreamer-1.0",
         "--sdk=org.gnome.Sdk//@@SDK_BRANCH@@",