review: Fixed -> Changed.

Signed-off-by: Piotr Sikora <[email protected]>

Author: PiotrSikora

CHANGELOG.md

@@ -6,7 +6,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ## [0.2.3] - 2025-06-04
 
-### Fixed
+### Changed
 
 - An empty value (`Some("")` or `Some([])`) is now returned when retrieving
   value of a HTTP header or trailer with an empty value. This is consistent