It contains a series of bugfixes and updates applied to libcurl's
`Curl_wait_ms()` over the years, but missed from the copy in
`tests/server/util.c`:
- d65321f939,
52e822173a,
5912da253b
- 4a8f459837
- 1ad49feb71
It fixes `wait_ms()` to check for, and return `SOCKERRNO`. Fixing error
handling on Windows.
Also:
- tests/server: change callers to check `SOCKERRNO`.
- `wait_ms()`: fix to check for the correct error code on Windows.
Pending for `Curl_wait_ms()`: #16621.
- `Curl_wait_ms()`: tidy-up `Sleep()` argument cast (nit).
- lib/curl_trc: drop an unused header.
Closes#16627
5681628e2d