[gtk-frdp] meson: Fix pkgconfig install dir

[Felipe Borges <felipeborges src gnome org>]

commit f59bdc456a7710629e67fed528dd343d17822ef2
Author: Felipe Borges <felipeborges gnome org>
Date:   Wed Jun 20 11:59:33 2018 +0200

    meson: Fix pkgconfig install dir

 src/meson.build | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/meson.build b/src/meson.build
index 23fc751..0874046 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -91,5 +91,5 @@ pkg.generate(
       version: meson.project_version(),
       subdirs: gtk_frdp_header_subdir,
      requires: 'glib-2.0',
-  install_dir: join_paths (libdir, 'pkgconfig')
+  install_dir: join_paths(get_option('libdir'), 'pkgconfig')
 )