Style: Replace header guards with #pragma once

modules/websocket/packet_buffer.h

@@ -28,8 +28,7 @@
 /* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
 /**************************************************************************/
 
-#ifndef PACKET_BUFFER_H
-#define PACKET_BUFFER_H
+#pragma once
 
 #include "core/templates/ring_buffer.h"
 
@@ -128,5 +127,3 @@ public:
 		clear();
 	}
 };
-
-#endif // PACKET_BUFFER_H