Update CHANGELOG.md

Author: tuj

CHANGELOG.md

@@ -4,7 +4,7 @@ All notable changes to this project will be documented in this file.
 
 ## Unreleased
 
-- [#139](https://github.com/os2display/display-client/pull/139)
+- [#140](https://github.com/os2display/display-client/pull/140)
   - Fixed issue where campaign end resulted in blank screen.
 
 ## [2.1.1] - 2024-10-23