[gnome-sdk-images] Disable parallel make when building gcab

[Emmanuele Bassi <ebassi src gnome org>]

commit 30ea06d9eb29711ebb0226e5917b846e9de5eed5
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Thu Jul 20 10:39:45 2017 +0100

    Disable parallel make when building gcab
    
    The gcab build terminates before the enumerations header can be
    generated because of race conditions and Autotools failing to
    generate an appropriate dependency.

 org.gnome.Sdk.json.in |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/org.gnome.Sdk.json.in b/org.gnome.Sdk.json.in
index 01a991f..092503e 100644
--- a/org.gnome.Sdk.json.in
+++ b/org.gnome.Sdk.json.in
@@ -590,6 +590,7 @@
         {
             "name": "gcab",
             "config-opts": ["--disable-static", "--enable-fast-install"],
+            "no-parallel-make": true,
             "sources": [
                 {
                     "type": "git",