Basic attempt at fixing #2368
Basic attempt at fixing #2368

Changing the method of updating and rewriting renewal config files
to use the same ConfigObj instance rather than a new one, and change
individual renewalparams items individually rather than replacing
the entire renewalparams dict with a new dict (which may also cause
a loss of associated comment data).

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