[gnome-control-center] build: Fix `USER_DIR_MODE` value in config.h

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 37a6b940cb83d97b808da77f397e34100beb263f
Author: Iñigo Martínez <inigomartinez gmail com>
Date:   Sat Apr 14 23:06:40 2018 +0200

    build: Fix `USER_DIR_MODE` value in config.h
    
    meson defines `USER_DIR_MODE` with a raw octal value to be used as
    the default permissions when creating the user's configuration
    directory.
    
    However, meson does not support raw octal values[0], so the define
    misses the initial `0` value. Due to this, the directory is created
    with wrong permissions.
    
    This has been changed to use the octal value as a string in meson,
    so the definition has the proper value.
    
    Fixes #49
    
    [0] https://github.com/mesonbuild/meson/issues/2047

 meson.build | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
---
diff --git a/meson.build b/meson.build
index fb74d04d1..ae1a897b3 100644
--- a/meson.build
+++ b/meson.build
@@ -44,7 +44,9 @@ foreach define: set_defines
   config_h.set_quoted(define[0], define[1])
 endforeach
 
-config_h.set('USER_DIR_MODE', 0700,
+# meson does not support octal values, so it must be handled as a
+# string. See: https://github.com/mesonbuild/meson/issues/2047
+config_h.set('USER_DIR_MODE', '0700',
              description: 'Permissions for creating the user\'s config, cache and data directories')
 
 # compiler flags