user32: Do not allow a change of capture if the currently capture window is a menu unless explicitly specified (try3)

[Peter Dons Tychsen]

Hey Paul,

Thanks for cleaning up the crashing 9x test-case so fast.

> This patch has introduced test failures on NT4 and below (tested locally):
> 
> http://test.winehq.org/data/tests/user32:win.html
Sorry for that.

> The callback is entered several times on NT4 (only once on XP) so it 
> seems. The test crashes on Win98 btw.
Even more sorry :-). I would seem that the test-case would do good with
a re-entry protection. Do you know where it crashes?

> You can use the winetestbot (https://winetestbot.geldorp.nl/) to check 
> the failures on NT4. I can assist with Win9x testing if needed.
I will check it out. Nice server!

> I'm busy setting up a local winetestbot that includes Win95, Win98 and 
> WinMe.
Great!

Thanks,

/pedro