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
When asked to resume a download, libcurl will convert that to HTTP logic
and if then the entire file is already transferred it will result in a
416 response from the HTTP server. With CURLOPT_FAILONERRROR set in that
scenario, it should *not* lead to an error return.
Updated test 1156, added test 1273
Reported-by: Jonathan Watt
Fixes#6740Closes#6753
