fix: add missing environment key in docker-compose.yaml

Add missing environment key before CASC_RELOAD_TOKEN variable in
jenkins_controller service. Same issue as build-docker-compose.yaml.

Author: gounthar

docker-compose.yaml

@@ -65,6 +65,7 @@ services:
       - dotnet
       - default
     # The CASC_RELOAD_TOKEN environment variable is used by the Jenkins controller to restart the Configuration as Code (JCasc) plugin configuration.
+    environment:
       - CASC_RELOAD_TOKEN=thisisnotsecure
     # The Jenkins web interface is exposed on port 8080.
     ports: