[gtk+] gdk: fix headers installation path

[Emmanuele Bassi <ebassi src gnome org>]

commit 807c744c8d5aa2bac0268c89f5201330d3a80b2f
Author: Marc-Antoine Perennou <Marc-Antoine Perennou com>
Date:   Tue May 23 10:32:27 2017 +0200

    gdk: fix headers installation path
    
    https://bugzilla.gnome.org/show_bug.cgi?id=782981
    
    Signed-off-by: Marc-Antoine Perennou <Marc-Antoine Perennou com>

 gdk/meson.build |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/gdk/meson.build b/gdk/meson.build
index 143f20d..0197538 100644
--- a/gdk/meson.build
+++ b/gdk/meson.build
@@ -103,7 +103,7 @@ gdk_enums = gnome.mkenums('gdkenumtypes',
   sources: gdk_public_headers,
   c_template : 'gdkenumtypes.c.template',
   h_template : 'gdkenumtypes.h.template',
-  install_dir : 'include/gtk-4.0/gdk',
+  install_dir: join_paths(gtk_includedir, 'gtk-4.0/gdk'),
   install_header : true)
 
 gdkenum_h = gdk_enums[1]
@@ -126,7 +126,7 @@ gdkconfig = configure_file(
   input  : 'gdkconfig.h.meson',
   output : 'gdkconfig.h',
   configuration : gdkconfig_cdata,
-  install_dir: 'include/gtk-4.0/gdk/')
+  install_dir: join_paths(gtk_includedir, 'gtk-4.0/gdk'))
 
 
 gdkversion_cdata = configuration_data()
@@ -138,7 +138,7 @@ gdkversionmacros = configure_file(
   input  : 'gdkversionmacros.h.in',
   output : 'gdkversionmacros.h',
   configuration: gdkversion_cdata,
-  install_dir: 'include/gtk-4.0/gdk/')
+  install_dir: join_paths(gtk_includedir, 'gtk-4.0/gdk'))
 
 gdkinc = include_directories('.')