Improve documentation of QWebEnginePage::acceptNavigationRequest

Change-Id: Ic4f91fa7927c18b53c6b0a0f69ee38905715eb10
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@theqtcompany.com>
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@theqtcompany.com>

src/webenginewidgets/doc/src/qwebenginepage_lgpl.qdoc

@@ -264,11 +264,11 @@
 
 /*!
     \fn bool acceptNavigationRequest(const QUrl &url, NavigationType type, bool isMainFrame)
+    \since 5.5
     This function is called upon receiving a request to navigate to the specified \a url by means of
     the specified navigation type \a type. \a isMainFrame indicates whether the request corresponds
     to the main frame or a sub frame. If the function returns \c true, the navigation request is
-    accepted and Chromium continues to load the page. Otherwise, the request is ignored. The default
-    implementation accepts the navigation request.
+    accepted and \c url is loaded. The default implementation accepts all navigation requests.
 */