[HttpClient] fix last fix

Author: nicolas-grekas

Response/AsyncResponse.php

@@ -206,11 +206,11 @@ public static function stream(iterable $responses, float $timeout = null, string
             foreach ($client->stream($wrappedResponses, $timeout) as $response => $chunk) {
                 $r = $asyncMap[$response];
 
-                if (null === $chunk->getError() && 0 === $r->offset) {
+                if (null === $chunk->getError()) {
                     if ($chunk->isFirst()) {
                         // Ensure no exception is thrown on destruct for the wrapped response
                         $r->response->getStatusCode();
-                    } elseif (null === $r->content && $chunk->isLast()) {
+                    } elseif (0 === $r->offset && null === $r->content && $chunk->isLast()) {
                         $r->content = fopen('php://memory', 'w+');
                     }
                 }