Save creating (and validating) a peer INET address if not required

[franz1981]

This is the twin of #4927

[franz1981]

in order to make this more effective I should change EndpointKey too and NOT enforce non-null peer address, to allow it to be null if ssl is disabled; while right now peerAddr should always be non null:

  EndpointKey(boolean ssl, ProxyOptions proxyOptions, SocketAddress serverAddr, SocketAddress peerAddr) {
    if (serverAddr == null) {
      throw new NullPointerException("No null server address");
    }
    if (peerAddr == null) {
      throw new NullPointerException("No null peer address");
    }
    this.ssl = ssl;
    this.proxyOptions = proxyOptions;
    this.peerAddr = peerAddr;
    this.serverAddr = serverAddr;
  }

let me know if I can proceed and push this forward till than