Update CHANGELOG.md

Author: mariusre

CHANGELOG.md

@@ -11,6 +11,7 @@
       - ADDED: flatbuffers output format support [#5513](https://github.com/Project-OSRM/osrm-backend/pull/5513)
       - ADDED: Global 'skip_waypoints' option [#5556](https://github.com/Project-OSRM/osrm-backend/pull/5556)
       - FIXED: Install the libosrm_guidance library correctly [#5604](https://github.com/Project-OSRM/osrm-backend/pull/5604)
+      - FIXED: Http Handler can now deal witch optional whitespace between header-key and -value [#5606](https://github.com
     - Routing:
       - CHANGED: allow routing past `barrier=arch` [#5352](https://github.com/Project-OSRM/osrm-backend/pull/5352)
       - CHANGED: default car weight was reduced to 2000 kg. [#5371](https://github.com/Project-OSRM/osrm-backend/pull/5371)