Use chain.pem instead of fullchain.pem

As some older OpenSSL (like the one in Debian 7) don't like the final cert being in the intermediate chain

root/etc/letsencrypt.sh/hooks_deploy_cert.d/10smeserver.sh

@@ -4,7 +4,7 @@
 DOM=${1}
 KEY=${2}
 CRT=${3}
-CHAIN=${4}
+CHAIN=${5}
 
 if [ -z "$DOM" -o -z "$KEY" -o -z "$CRT" -o -z "$CHAIN" ]; then
   echo "Usage: $0 domain /path/to/key /path/to/cert /path/to/chain" >&2