[gsettings-desktop-schemas] build: Fix include dir in meson-generated .pc file

[Carlos Garnacho <carlosg src gnome org>]

commit c1b3cc5d625776b2d2f84082fd6ad4cc225549b7
Author: Carlos Garnacho <carlosg gnome org>
Date:   Tue Dec 11 15:41:58 2018 +0100

    build: Fix include dir in meson-generated .pc file
    
    Missing the last 'gsettings-desktop-schemas' bit.

 meson.build | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/meson.build b/meson.build
index 03183ab..3bb9efd 100644
--- a/meson.build
+++ b/meson.build
@@ -32,6 +32,7 @@ gnome = import('gnome')
 pkg = import('pkgconfig')
 
 pkg.generate(name: gsettings_desktop_schemas_name,
+             subdirs: gsettings_desktop_schemas_name,
              install_dir: join_paths(datadir, 'pkgconfig'),
              version: gsettings_desktop_schemas_version,
              description: 'Shared GSettings schemas for the desktop, including helper headers')