remove stray references to DV challs in auth_handler
remove stray references to DV challs in auth_handler

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