TCPPort's incoming_only_ member seems unused and there was a TODO
about this. This CL just removes it.
Bug: webrtc:10198
Change-Id: I216c291159a32fa2924309affa3769a4be116fd0
Reviewed-on: https://webrtc-review.googlesource.com/c/120931
Reviewed-by: Steve Anton <steveanton@webrtc.org>
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#26538}