[2/2] winhttp: Always drain content before sending the next request.

[Marvin]

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=30141

Your paranoid android.


=== w2003std (32 bit winhttp) ===
winhttp.c:1143: Test failed: request failed unexpectedly 400