Remove private API warning from qwebengineurlrequestjob.h

Change-Id: Ie2c9e3ac60790e49a449c473cd9fb60ef698b6de
Reviewed-by: Michael Brüning <michael.bruning@theqtcompany.com>

src/core/api/qwebengineurlrequestjob.h

@@ -37,17 +37,6 @@
 #ifndef QWEBENGINEURLREQUESTJOB_H
 #define QWEBENGINEURLREQUESTJOB_H
 
-//
-//  W A R N I N G
-//  -------------
-//
-// This file is not part of the Qt API.  It exists purely as an
-// implementation detail.  This header file may change from version to
-// version without notice, or even be removed.
-//
-// We mean it.
-//
-
 #include "qtwebenginecoreglobal.h"
 
 #include <QtCore/qbytearray.h>