fix: quote boolean environment variables in Docker Compose

Author: vincentchalamon

compose.override.yaml

@@ -61,7 +61,7 @@ services:
       KEYCLOAK_URL: http://php/oidc/
       KEYCLOAK_USER: ${KEYCLOAK_ADMIN_USER:-admin}
       KEYCLOAK_PASSWORD: ${KEYCLOAK_ADMIN_PASSWORD:-!ChangeMe!}
-      KEYCLOAK_AVAILABILITYCHECK_ENABLED: true
+      KEYCLOAK_AVAILABILITYCHECK_ENABLED: "true"
       KEYCLOAK_AVAILABILITYCHECK_TIMEOUT: 120s
       IMPORT_FILES_LOCATIONS: "/config/*"
     depends_on: