replace ${CERTDIR}/${domain} with ${certdir} everywhere
replace ${CERTDIR}/${domain} with ${certdir} everywhere

• improves readability
• allows ${certdir} to be changed independent from ${domain} more easily

dennisschuerholz/dehydrated,Rayne/letsencrypt.sh,ahnooie/dehydrated,lukas2511/dehydrated,lukas2511/letsencrypt.sh,erorus/letsencrypt.sh