h2load: Call session->on_write() explicitly in Client::on_connect()
nghttpx: Remove per-connection rate limit

It looks like setting read-rate and read-burst to 0 makes busy loop.
It seems a bug.  On the other hand, we most likely want per-thread
rate limit rather than per-connection.  So we decided to drop them.
nghttpx: Remove TLSv1.0 from default TLS proto list
nghttpx: Update cipher suite list
nghttp: Remove garbage for deprecated per-stream compression which cause leak
h2load: Fix memory leak detected by LeakSanitizer