Authentication dialog is displayed even when the page requires no authentication in a certain scenario

Precondition:
-------------
Connect the device to WLAN/GPRS network.

Steps to Reproduce:
-------------------
1. Open a URL:
"http://testsuite.nokia-boston.com/content/http_StatusCodes_4xx/get401_1.asp"
2. Activate the link "get 401: Step 2"
3. Authentication dialog should be open. Tap on Cancel button in the
authentication dialog.
4. Authentication dialog disappears.
5. Load any link from TCG - "testsuite.nokia-boston.com" eg: URL:
"http://testsuite.nokia-boston.com/content/http_StatusCodes_4xx/get402_1.asp"

Expected Outcome:
-----------------
Authentication dialog should not be opened.
Page should be opened properly with the title "get 402: Step 1"

Actual Outcome:
---------------
Authentication dialog is opened
Second link opened properly without doing the step1 to step4.

Note:

Windows: Yes (r17698-trunk)
Mozilla: No
Safari: No

Comment:
In case of user cancels credential request QAuthenticator is not filled in
signal void authenticationRequired ( QNetworkReply * reply, QAuthenticator *
authenticator ) call, even then QNetworkAccessManager sends authentication
information to server and stores credential information even server sends
forbidden message back to client.

When page in same domain are called QNetworkAccessManager sends stored
credential information to server and because that is not valid server want
update credentials, which cause second call of signal
authenticationRequired(...), which shows credential dialog again.