[metacity] window-props: don't reload INIT_ONLY properties

[Alberts Muktupāvels <muktupavels src gnome org>]

commit d7aa2acaff7a05f05889f9fa834ecd16e907ce5a
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Sun Feb 26 21:20:28 2017 +0200

    window-props: don't reload INIT_ONLY properties
    
    Missing part from mutter commit:
    https://git.gnome.org/browse/mutter/commit/?id=b87db00fdb550ebb40288dd2f0f76010ab2df554

 src/core/window-props.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/src/core/window-props.c b/src/core/window-props.c
index 136311d..8e7f049 100644
--- a/src/core/window-props.c
+++ b/src/core/window-props.c
@@ -102,6 +102,9 @@ meta_window_reload_property_from_xwindow (MetaWindow *window,
   if (!hooks)
     return;
 
+  if ((hooks->flags & INIT_ONLY) && !initial)
+    return;
+
   init_prop_value (window, hooks, &value);
 
   meta_prop_get_values (window->display, xwindow,