Wholesale conversion to #pragma once

Kudos to cgmb and https://github.com/cgmb/guardonce

Change-Id: Ifa8970734b8d43fd08c9260c645bdb0228633791
Reviewed-by: Tobias Hunger <tobias.hunger@theqtcompany.com>

src/libs/sqlite/sqlitetransaction.h

@@ -23,8 +23,7 @@
 **
 ****************************************************************************/
 
-#ifndef SQLITETRANSACTION_H
-#define SQLITETRANSACTION_H
+#pragma once
 
 #include "sqliteglobal.h"
 
@@ -60,6 +59,3 @@ public:
     SqliteExclusiveTransaction();
 
 };
-
-
-#endif // SQLITETRANSACTION_H