compile fix for Windows phone

Change-Id: Icdcadfd31d0b564ba8fdd89aab7472b2e4aaed22
Reviewed-by: Andrew Knight <andrew.knight@digia.com>
Reviewed-by: Oliver Wolff <oliver.wolff@digia.com>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>