  "mempoolminfee": 0.00000000

When the minrelaytxfee is > 0.

"\nArguments:\n"
            "1. timeout (int, optional, default=0) Time in milliseconds to wait for a response. 0 indicates no timeout.\n"
            "\nResult:\n"
            "{                           (json object)\n"
            "  \"hash\" : {       (string) The blockhash\n"
            "  \"height\" : {     (int) Block height\n"
            "}\n"
            "\nExamples:\n"
            + HelpExampleCli("waitfornewblock", "1000")
            + HelpExampleRpc("waitfornewblock", "1000")
        );
    int timeout = 0;
    if (!request.params[0].isNull())
        timeout = request.params[0].get_int();
    CUpdatedBlock block;
    {
        std::unique_lock<std::mutex> lock(cs_blockchange);
        block = latestblock;
        if(timeout)
            cond_blockchange.wait_for(lock, std::chrono::milliseconds(timeout), [&block]{return latestblock.height != block.height || latestblock.hash != block.hash || !IsRPCRunning(); });
        else
            cond_blockchange.wait(lock, [&block]{return latestblock.height != block.height || latestblock.hash != block.hash || !IsRPCRunning(); });
        block = latestblock;
    }
    UniValue ret(UniValue::VOBJ);
    ret.push_back(Pair("hash", block.hash.GetHex()));
    ret.push_back(Pair("height", block.height));
    return ret;
}
UniValue waitforblock(const JSONRPCRequest& request)