[PATCH] httpapi/tests: Use CancelIo to avoid a test failure on Windows XP.

[Marvin]

Hi,

While running your changed tests, 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=57050

Your paranoid android.


=== debian10 (32 bit Chinese:China report) ===

httpapi:
httpapi.c:337: Test failed: Got error 31.
httpapi.c:87: Test failed: Failed to connect socket, error 10061.
httpapi.c:346: Test failed: send() returned -1.
httpapi.c:350: Test failed: Got error 258.
httpapi.c:351: Test failed: OVERLAPPED pointers didn't match.
httpapi.c:352: Test failed: Got unexpected key 3735928559.
httpapi.c:363: Test failed: Got error 1229.
httpapi.c:367: Test failed: Got error 1229.
httpapi.c:375: Test failed: Got error 2.