fix header duplication issue
fix header duplication issue

Change-Id: I884bf24eb9eed9a131af0da36a858588e5b2d51b
Reviewed-on: http://cr.qtquick.me/417
Tested-by: http://ci.qtquick.me/
Reviewed-by: Tasuku Suzuki <42980d970444f9101663582e70cd53623b3238b4@gmail.com>
Tested-by: Tasuku Suzuki <42980d970444f9101663582e70cd53623b3238b4@gmail.com>

qt-users-jp/qthttpserver,qt-users-jp/qthttpserver