mshtml: Correctly handle S_OK with NULL URL return from TranslateUrl.

[Jacek Caban]

On 02/25/15 13:10, Marvin wrote:
> Hi,
>
> While running your changed tests on Windows, I think I found new failures.
> Being a bot and all I'm not very good at pattern recognition, so I might be
> wrong, but could you please double-check?
> Full results can be found at
> https://testbot.winehq.org/JobDetails.pl?Key=11724
>
> Your paranoid android.
>
>
> === wvistau64 (32 bit htmldoc) ===
> The test timed out

This seems random and unrelated:
https://testbot.winehq.org/JobDetails.pl?Key=11725

Jacek