...after the method line:
"Since the Host field-value is critical information for handling a
request, a user agent SHOULD generate Host as the first header field
following the request-line." / RFC 7230 section 5.4
Additionally, this will also make libcurl ignore multiple specified
custom Host: headers and only use the first one. Test 1121 has been
updated accordingly
Bug: http://curl.haxx.se/bug/view.cgi?id=1491
Reported-by: Rainer Canavan
Verifies that the change in 68f0166a92 works as intended and that
different HTTP auth credentials to the same host still re-uses the
connection properly.
