Use #pragma once instead of include guards

src/gui/properties/downloadedpiecesbar.h

@@ -26,8 +26,7 @@
  * exception statement from your version.
  */
 
-#ifndef DOWNLOADEDPIECESBAR_H
-#define DOWNLOADEDPIECESBAR_H
+#pragma once
 
 #include <QBitArray>
 #include <QtContainerFwd>
@@ -63,5 +62,3 @@ private:
     QBitArray m_pieces;
     QBitArray m_downloadedPieces;
 };
-
-#endif // DOWNLOADEDPIECESBAR_H