Log field sstc is not accurate when port is transparent

[shinrich]

Observed this while testing traffic through a ssl port with tr-full. Also configured to proxy.config.http.attach_server_session_to_client to 1, so the origin session is attached to the client session for reuse. Based on the debug logs, the attached origin session is being reused, but in the access.log, the value of % is always 1.

[github-actions[bot]]

This issue has been automatically marked as stale because it has not had recent activity. Marking it stale to flag it for further consideration by the community.