message: Fix Bug: libcurl transport layer hangs on 304 response
diff: @@ -705,7 +705,8 @@ void CurlSession::ReadStatusLineAndHeadersFromRawResponse(
  // For NoContent status code, also need to set contentLength to 0.
  // https://github.com/Azure/azure-sdk-for-cpp/issues/406
  if (this->m_request.GetMethod() == HttpMethod::Head
  - || this->m_lastStatusCode == HttpStatusCode::NoContent)
  + || this->m_lastStatusCode == HttpStatusCode::NoContent
  + || this->m_lastStatusCode == HttpStatusCode::NotModified)
  {
  this->m_contentLength = 0;
  this->m_bodyStartInBuffer = _detail::DefaultLibcurlReaderSize;
  