Fix GitHub username for Chris Stephenson

Signed-off-by: Mathieu Benoit <mathieu-benoit@hotmail.fr>

Author: mathieu-benoit

MAINTAINERS.md

@@ -3,6 +3,6 @@
 The following is the list of maintainers for all Score repositories, in alphabetical order:
 
 - Ben Meier (Oracle) [@astromechza](https://github.com/astromechza)
-- Chris Stephenson (Independent) [@chrishumanitec](https://github.com/chris-stephenson)
+- Chris Stephenson (Independent) [@chris-stephenson](https://github.com/chris-stephenson)
 - Mathieu Benoit (Docker) [@mathieu-benoit](https://github.com/mathieu-benoit)
 - Susa Tünker (Checkly) [@sujaya-sys](https://github.com/sujaya-sys)