simplify error handling
simplify error handling

stweil/letsencrypt,brentdax/letsencrypt,DavidGarciaCat/letsencrypt,bsmr-misc-forks/letsencrypt,bsmr-misc-forks/letsencrypt,letsencrypt/letsencrypt,wteiken/letsencrypt,jtl999/certbot,jtl999/certbot,wteiken/letsencrypt,brentdax/letsencrypt,dietsche/letsencrypt,jsha/letsencrypt,stweil/letsencrypt,jsha/letsencrypt,letsencrypt/letsencrypt,lmcro/letsencrypt,dietsche/letsencrypt,lmcro/letsencrypt,mitnk/letsencrypt,mitnk/letsencrypt,DavidGarciaCat/letsencrypt