The threee tags `<name>`, `</name>` and `<command>` were frequently used
with a leading space that this removes. The reason this habbit is so
widespread in testcases is probably that they have been copy and pasted.
Hence, fixing them all now might curb this practice from now on.
Closes#12028
...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