Introduce independent_listener, will be used for both IPv4 and IPv6 connections.
Introduce independent_listener, will be used for both IPv4 and IPv6
connections.

zabracks/sshuttle,dushmis/sshuttle,shaunstanislaus/sshuttle,dushmis/sshuttle,zabracks/sshuttle,shaunstanislaus/sshuttle,GrimDerp/sshuttle,zabracks/sshuttle,sshuttle/sshuttle,apenwarr/sshuttle,xtaran/sshuttle,dxq-git/sshuttle,xtaran/sshuttle,dxq-git/sshuttle,sshuttle/sshuttle,apenwarr/sshuttle,dushmis/sshuttle,xtaran/sshuttle,dxq-git/sshuttle,GrimDerp/sshuttle,shaunstanislaus/sshuttle,GrimDerp/sshuttle