Suggested by @MarcoFalke after #14627 and possibly #14420. We should warn if an unrecognised/incorrect section is present in bitcoin.conf. i.e `[testnet]` is present instead of `[test]`.
{
    LOCK(cs_args);
    m_network = network;
}
bool ArgsManager::ParseParameters(int argc, const char* const argv[], std::string& error)
{
    LOCK(cs_args);
    m_override_args.clear();
    for (int i = 1; i < argc; i++) {
        std::string key(argv[i]);
        std::string val;
        size_t is_index = key.find('=');
        if (is_index != std::string::npos) {
            val = key.substr(is_index + 1);
            key.erase(is_index);
        }
#ifdef WIN32
        std::transform(key.begin(), key.end(), key.begin(), ::tolower);
        if (key[0] == '/')
            key[0] = '-';
#endif
        if (key[0] != '-')
            break;