Fix a warning in QWebEnginePage::setHtml

Change-Id: I87c18edb89658433d6dc3487ab92d2ff7bd6c986
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>

src/webenginewidgets/api/qwebenginepage.cpp

@@ -524,7 +524,6 @@ void QWebEnginePage::toPlainText(const QWebEngineCallback<const QString &> &resu
 
 void QWebEnginePage::setHtml(const QString &html, const QUrl &baseUrl)
 {
-    Q_D(QWebEnginePage);
     setContent(html.toUtf8(), QStringLiteral("text/html;charset=UTF-8"), baseUrl);
 }