fix: set both log and logs

Somehow the documentation is inconsistent on this feature:
verdaccio/verdaccio@b1d258b

The release note seems to suggest that `log` is the correct key:
https://github.com/verdaccio/verdaccio/releases/tag/v5.22.1

But according to my test, only `logs` works.

Anyway, let's keep both so that it surely works.

verdaccio.yaml

@@ -60,3 +60,4 @@ packages:
     proxy: npmjs
 
 log: { type: stdout, format: pretty, level: warn }
+logs: { type: stdout, format: pretty, level: warn }