[gnome-control-center] common: Fix build by providing dummy header

[Rui Matos <rtcm src gnome org>]

commit 3c41d02b09b20eba8edc23b09a9621735aaf7d50
Author: Bastien Nocera <hadess hadess net>
Date:   Wed Jan 21 13:07:45 2015 +0100

    common: Fix build by providing dummy header
    
    https://bugzilla.gnome.org/show_bug.cgi?id=743266

 panels/common/Makefile.am          |    3 ++-
 panels/common/gnome-settings-bus.h |   12 ++++++++++++
 2 files changed, 14 insertions(+), 1 deletions(-)
---
diff --git a/panels/common/Makefile.am b/panels/common/Makefile.am
index efb0704..575fd03 100644
--- a/panels/common/Makefile.am
+++ b/panels/common/Makefile.am
@@ -52,7 +52,8 @@ libdevice_la_SOURCES =                        \
        gsd-device-manager.c            \
        gsd-device-manager.h            \
        gsd-device-manager-x11.c        \
-       gsd-device-manager-x11.h
+       gsd-device-manager-x11.h        \
+       gnome-settings-bus.h
 
 libdevice_la_LIBADD =                  \
        $(DEVICES_LIBS)
diff --git a/panels/common/gnome-settings-bus.h b/panels/common/gnome-settings-bus.h
new file mode 100644
index 0000000..0698f01
--- /dev/null
+++ b/panels/common/gnome-settings-bus.h
@@ -0,0 +1,12 @@
+/* Stub to replace gnome-settings-daemon's
+ * gnome-settings-bus.h helpers */
+
+#include <gdk/gdkx.h>
+
+#define HAVE_WAYLAND 1
+
+static inline gboolean
+gnome_settings_is_wayland (void)
+{
+  return !GDK_IS_X11_DISPLAY (gdk_display_get_default ());
+}