Move the connection back to the connection pool when HTTP error 404 was received (#5308)

* Move the connection back to the connection pool when HTTP error 404 was received

* Use symbolic name for 404 status code

Author: mchelnokov

sdk/core/azure-core/src/http/curl/curl.cpp

@@ -2132,8 +2132,7 @@ void CurlConnectionPool::MoveConnectionBackToPool(
     HttpStatusCode lastStatusCode)
 {
   auto code = static_cast<std::underlying_type<Http::HttpStatusCode>::type>(lastStatusCode);
-  // laststatusCode = 0
-  if (code < 200 || code >= 300)
+  if ((code < 200 || code >= 300) && lastStatusCode != HttpStatusCode::NotFound)
   {
     // A handler with previous response with Error can't be re-use.
     return;