message: util: Check if specified config file cannot be opened
diff: @@ -905,6 +905,11 @@ bool ArgsManager::ReadConfigFiles(std::string& error, bool ignore_invalid_keys)
  const std::string confPath = GetArg("-conf", BITCOIN_CONF_FILENAME);
  fsbridge::ifstream stream(GetConfigFile(confPath));
  + // not ok to have a config file specified that cannot be opened
  + if (IsArgSet("-conf") && !stream.good()) {
  + error = strprintf("specified config file \"%s\" could not be opened.", confPath);
  + return false;
  + }
  // ok to not have a config file
  if (stream.good()) {
  if (!ReadConfigStream(stream, confPath, error, ignore_invalid_keys)) {
  