[gnome-control-center] universal-access: Replace ifdefs with #pragma once

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 6b2ed3a4bceb2b2a2519790bda1b6e05ce75ea48
Author: Robert Ancell <robert ancell canonical com>
Date:   Wed May 30 13:27:43 2018 +1200

    universal-access: Replace ifdefs with #pragma once

 panels/universal-access/cc-ua-panel.h | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)
---
diff --git a/panels/universal-access/cc-ua-panel.h b/panels/universal-access/cc-ua-panel.h
index b8c467eaf..6d925fa1d 100644
--- a/panels/universal-access/cc-ua-panel.h
+++ b/panels/universal-access/cc-ua-panel.h
@@ -19,9 +19,7 @@
  *
  */
 
-
-#ifndef _CC_UA_PANEL_H
-#define _CC_UA_PANEL_H
+#pragma once
 
 #include <shell/cc-panel.h>
 
@@ -31,5 +29,3 @@ G_BEGIN_DECLS
 G_DECLARE_FINAL_TYPE (CcUaPanel, cc_ua_panel, CC, UA_PANEL, CcPanel)
 
 G_END_DECLS
-
-#endif /* _CC_UA_PANEL_H */