`RewindBlockIndex` was made to allow nodes upgrading to new consensus rules post-segwit fork to 
download new consensus data (i.e witnesses) without having to go through a whole IBD. It has been pointed than now really few pre-segwit nodes care to upgrade and that this logic may be irrelevant.

See https://github.com/bitcoin/bitcoin/pull/17737#discussion_r358514335 in review  of #17737 for more context pointers.
SetReachable(net, false);
        }
    }
    
    fNameLookup = args.GetBoolArg("-dns", DEFAULT_NAME_LOOKUP);
    bool proxyRandomize = args.GetBoolArg("-proxyrandomize", DEFAULT_PROXYRANDOMIZE);
    
    
    std::string proxyArg = args.GetArg("-proxy", "");
    SetReachable(NET_ONION, false);
    if (proxyArg != "" && proxyArg != "0") {
        CService proxyAddr;
        if (!Lookup(proxyArg, proxyAddr, 9050, fNameLookup)) {
            return InitError(strprintf(_("Invalid -proxy address or hostname: '%s'"), proxyArg));
        }
        proxyType addrProxy = proxyType(proxyAddr, proxyRandomize);
        if (!addrProxy.IsValid())
            return InitError(strprintf(_("Invalid -proxy address or hostname: '%s'"), proxyArg));
        SetProxy(NET_IPV4, addrProxy);
        SetProxy(NET_IPV6, addrProxy);
        SetProxy(NET_ONION, addrProxy);
        SetNameProxy(addrProxy);
        SetReachable(NET_ONION, true); 
    }
    
    
    
    std::string onionArg = args.GetArg("-onion", "");
    if (onionArg != "") {
        if (onionArg == "0") {