This check must be done only when we are sure the request was
successfully sent. soup_session_send() might fail without setting the
status code. In this case status code is 0 so we would only catch the
error after the seek range check. In this case we would report an error
saying that the seek range was not respected, instead of reporting the
underlying error that triggered the soup_session_send() failure.
https://bugzilla.gnome.org/attachment.cgi?bugid=777222