Fix #794 by removing the length check because it's not always possibl…

…e to determine this.

src/Flurl.Http/Configuration/DefaultJsonSerializer.cs

@@ -35,6 +35,9 @@ public DefaultJsonSerializer(JsonSerializerOptions options = null) {
  /// Deserializes the specified stream to an object of type T.
  /// </summary>
  /// <param name="stream">The stream to deserialize.</param>
- public T Deserialize<T>(Stream stream) => stream.Length == 0 ? default : JsonSerializer.Deserialize<T>(stream, _options);
+ public T Deserialize<T>(Stream stream)
+ {
+ return JsonSerializer.Deserialize<T>(stream, _options);
+ }
  }
-}
+}