Doc: Bump QtWebEngine import version

Change-Id: Ice026456c9dcc1688ef76cf3f556342b7a0a2ecf
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>

src/webengine/doc/src/qtwebengine-qmlmodule.qdoc

 /****************************************************************************
 **
-** Copyright (C) 2017 The Qt Company Ltd.
+** Copyright (C) 2018 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
@@ -26,7 +26,7 @@
 ****************************************************************************/
 
 /*!
-    \qmlmodule QtWebEngine 1.5
+    \qmlmodule QtWebEngine 1.7
     \title Qt WebEngine QML Types
     \brief Provides QML types for rendering web content within a QML application
     \ingroup qtwebengine-modules
@@ -36,7 +36,7 @@
     your .qml file:
 
     \badcode
-    import QtWebEngine 1.5
+    import QtWebEngine 1.7
     \endcode
 
     To link against the module, add the following QT variable to your qmake .pro