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
"Connection: close" and actually close the connection after the
response-body, libcurl could still have outstanding data to send and it
would not properly notice this and stop sending. This caused weirdness and
sad faces. http://curl.haxx.se/bug/view.cgi?id=2080222
Note that there are still reasons to consider libcurl's behavior when
getting a >= 400 response code while sending data, as Craig Perras' note
"http upload: how to stop on error" specifies:
http://curl.haxx.se/mail/archive-2008-08/0138.html