[gnome-builder] flatpak: use --libdir=lib

[Christian Hergert <chergert src gnome org>]

commit 0fd16f93f769cf419092dee8d891e4a8893487d1
Author: Christian Hergert <chergert redhat com>
Date:   Tue Jan 30 22:40:48 2018 -0800

    flatpak: use --libdir=lib
    
    We probably don't actually need this anymore with modern flatpak
    builder/sdk changes. But until I can verify that...

 build-aux/flatpak/org.gnome.Builder.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/build-aux/flatpak/org.gnome.Builder.json b/build-aux/flatpak/org.gnome.Builder.json
index 6b9979124..f82d02309 100644
--- a/build-aux/flatpak/org.gnome.Builder.json
+++ b/build-aux/flatpak/org.gnome.Builder.json
@@ -711,7 +711,7 @@
             "buildsystem" : "meson",
             "builddir" : true,
             "config-opts" : [
-                "--libdir=/app/lib",
+                "--libdir=lib",
                 "--buildtype=debugoptimized",
                 "-Denable_tracing=true",
                 "-Dwith_help=true",