[gnome-sdk-images] Don't load Sdk extensions in the Platform

[Mathieu Bridon <mbridon src gnome org>]

commit 03457067d6894e0edbcefcfc6f88a73991ff1f1c
Author: Mathieu Bridon <bochecha daitauha fr>
Date:   Wed Aug 1 14:42:45 2018 +0200

    Don't load Sdk extensions in the Platform
    
    This had been in the stable branch back in May, but no in master.

 org.gnome.Sdk.json.in | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
---
diff --git a/org.gnome.Sdk.json.in b/org.gnome.Sdk.json.in
index 84c7517..fb0b294 100644
--- a/org.gnome.Sdk.json.in
+++ b/org.gnome.Sdk.json.in
@@ -15,9 +15,11 @@
         "org.freedesktop.Platform.Icontheme",
         "org.freedesktop.Platform.VAAPI.Intel",
         "org.freedesktop.Platform.ffmpeg",
-        "org.freedesktop.Sdk.Extension",
         "org.gtk.Gtk3theme"
     ],
+    "inherit-sdk-extensions": [
+        "org.freedesktop.Sdk.Extension"
+    ],
     "add-extensions": {
         "org.gnome.Sdk.Docs" : {
             "directory": "share/runtime/docs",