Its sole remaining purpose was to display "proxy foo started", which
has little benefit and pollutes output for those with plenty of proxies.
Let's remove it now.
The VTCs were updated to reflect this, because many of them had explicit
counts of dropped lines to match this message.
This is tagged as MEDIUM because some users may be surprized by the
loss of this quite old message.
For http-check send rules, it is now possible to use a log-format string to set
the request's body. the keyword "body-lf" should be used instead of "body". If the
string eval fails, no body is added.
For http-check send rules, it is now possible to use a log-format string to set
the request URI. the keyword "uri-lf" should be used instead of "uri". If the
string eval fails, we fall back on the default uri "/".
