[gnome-sdk-images] Fix the glib2 build

[Mathieu Bridon <mbridon src gnome org>]

commit 7de47d58afa8690eca734fde977e108a2776252c
Author: Mathieu Bridon <bochecha daitauha fr>
Date:   Mon Jul 17 10:46:58 2017 +0200

    Fix the glib2 build
    
    Thanks to ebassi for the recommandation to build with Python 3.

 org.gnome.Sdk.json.in |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/org.gnome.Sdk.json.in b/org.gnome.Sdk.json.in
index 5ff991a..01a991f 100644
--- a/org.gnome.Sdk.json.in
+++ b/org.gnome.Sdk.json.in
@@ -103,7 +103,7 @@
         },
         {
             "name": "glib",
-            "config-opts": [ "--with-pcre=system" ],
+            "config-opts": [ "--with-pcre=system", "--with-python=python3" ],
             "ensure-writable": [ "/share/glib-2.0/codegen/*.pyc" ],
             "cleanup-platform": [ "/share/glib-2.0/codegen",
                                   "/bin/gdbus-codegen",