Fix documentation build failures (#5068)
Fix documentation build failures (#5068)

* sphinxify error_handler docs
letsencrypt/letsencrypt,stweil/letsencrypt,letsencrypt/letsencrypt,lmcro/letsencrypt,lmcro/letsencrypt,stweil/letsencrypt,jsha/letsencrypt,jsha/letsencrypt