[gnome-sdk-images] dconf: Fix option usage

[Mathieu Bridon <mbridon src gnome org>]

commit 90967209c5d007638a5da7aba7fc513d9b1e05ac
Author: Mathieu Bridon <bochecha daitauha fr>
Date:   Sun Aug 12 17:24:15 2018 +0200

    dconf: Fix option usage
    
    In Meson, options have a single hyphen, not two.

 org.gnome.Sdk.json.in | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/org.gnome.Sdk.json.in b/org.gnome.Sdk.json.in
index 8163210..be61201 100644
--- a/org.gnome.Sdk.json.in
+++ b/org.gnome.Sdk.json.in
@@ -203,7 +203,7 @@
         {
             "name": "dconf",
             "buildsystem": "meson",
-            "config-opts": [ "--Dbash_completion=false" ],
+            "config-opts": [ "-Dbash_completion=false" ],
             "cleanup": [ "/libexec/dconf-service", "/share/dbus-1/services/*" ],
             "sources": [
                 {