Spurious error message at initialization

When calling init_key_issuer() with read_only parameter set to true (or without this parameter, as this is the default value), an error message is loggued:
[ERROR] [cryptojwt.key_issuer.init_key_issuer] Not allowed to write to disc!

It seems a bit exaggerated to qualify this as an error, whereas it is just the expected behaviour. I'd rather use INFO or DEBUG level, to avoid false alert.