[stable/2023.2] Drop extra log_config_append for Nova (#1372)

Co-authored-by: Mohammed Naser <mnaser@vexxhost.com>
diff --git a/roles/nova/vars/main.yml b/roles/nova/vars/main.yml
index 7f8317d..585e4d9 100644
--- a/roles/nova/vars/main.yml
+++ b/roles/nova/vars/main.yml
@@ -105,7 +105,6 @@
         auth_schemes: vencrypt,none
     nova_ironic:
       DEFAULT:
-        log_config_append: null
         force_config_drive: true
   manifests:
     deployment_consoleauth: false