[gnome-control-center] online-accounts: Replace ifdefs with #pragma once

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

commit df85304107bc00f56bc4a551b2087d7f0a3d00dd
Author: Robert Ancell <robert ancell canonical com>
Date:   Thu Nov 21 20:38:58 2019 +1300

    online-accounts: Replace ifdefs with #pragma once

 panels/online-accounts/cc-online-accounts-panel.h | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)
---
diff --git a/panels/online-accounts/cc-online-accounts-panel.h 
b/panels/online-accounts/cc-online-accounts-panel.h
index d44ff0cd9..68d5e93d1 100644
--- a/panels/online-accounts/cc-online-accounts-panel.h
+++ b/panels/online-accounts/cc-online-accounts-panel.h
@@ -18,8 +18,7 @@
  * Author: David Zeuthen <davidz redhat com>
  */
 
-#ifndef __GOA_PANEL_H__
-#define __GOA_PANEL_H__
+#pragma once
 
 #include <shell/cc-panel.h>
 
@@ -30,5 +29,3 @@ G_BEGIN_DECLS
 G_DECLARE_FINAL_TYPE (CcGoaPanel, cc_goa_panel, CC, GOA_PANEL, CcPanel)
 
 G_END_DECLS
-
-#endif /* __GOA_PANEL_H__ */