interface: IConfig is missing fields used in client.py (#4453)
interface: IConfig is missing fields used in client.py (#4453)

Signed-off-by: Arthur Gautier <f88c5e35ba2b44ad8184caf58e04d88fd477a72f@gandi.net>
jsha/letsencrypt,stweil/letsencrypt,lmcro/letsencrypt,letsencrypt/letsencrypt,stweil/letsencrypt,jsha/letsencrypt,lmcro/letsencrypt,letsencrypt/letsencrypt