RPC bumpfee with an explicit feerate using `conf_target` and `estimate_mode` errors with `JSONRPCException: JSON integer out of range (-1)`.
{
    std::string ret;
    ret += "(";
    if (m_type_str.size() != 0) {
        ret += m_type_str.at(1);
    } else {
        switch (m_type) {
        case Type::STR_HEX:
        case Type::STR: {
            ret += "string";
            break;
        }
        case Type::NUM: {
            ret += "numeric";
            break;
        }
        case Type::AMOUNT: {
            ret += "numeric or string";
            break;
        }
        case Type::RANGE: {
            ret += "numeric or array";
            break;
        }
        case Type::BOOL: {
            ret += "boolean";
            break;
        }
        case Type::OBJ: