[glade] GladeProperty: replace deprecated macro

[Juan Pablo Ugarte <jpu src gnome org>]

commit f5e800eca8ffb277dcc31d293c76664990bba79c
Author: Juan Pablo Ugarte <juanpablougarte gmail com>
Date:   Wed Jun 10 17:27:14 2020 -0300

    GladeProperty: replace deprecated macro

 gladeui/glade-property.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)
---
diff --git a/gladeui/glade-property.c b/gladeui/glade-property.c
index c7df0db0..46ff8684 100644
--- a/gladeui/glade-property.c
+++ b/gladeui/glade-property.c
@@ -634,9 +634,7 @@ glade_property_finalize (GObject *object)
 static void
 glade_property_init (GladeProperty *property)
 {
-  property->priv = G_TYPE_INSTANCE_GET_PRIVATE (property,
-                                                GLADE_TYPE_PROPERTY,
-                                                GladePropertyPrivate);
+  property->priv = glade_property_get_instance_private (property);
 
   property->priv->precision = 2;
   property->priv->enabled = TRUE;