Update docs/configuring-playbook-user-verification-service.md: use the variable specified on main.yml directly

There are other variables specified on .env.j2 such as UVS_ACCESS_TOKEN and UVS_AUTH_TOKEN, but these are not used in the description on the document other than UVS_LOG_LEVEL. This commit therefore replaces the variable with the one specified on main.yml (matrix_user_verification_service_uvs_log_level) to improve consistency.

Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>

docs/configuring-playbook-user-verification-service.md

@@ -121,7 +121,7 @@ The default logging level for this component is `info`. If you want to increase
 
 ```yaml
 # See choices here: https://github.com/winstonjs/winston#logging-levels
-UVS_LOG_LEVEL: debug
+matrix_user_verification_service_uvs_log_level: debug
 ```
 
 ### TLS Certificate Checking