fix(backup): ssl dir renamed to certs

MR !9

include/bin/backup.sh

@@ -8,7 +8,7 @@ back_file_name="mail_server-$backup_version-$(date +%Y-%m-%d-%H%M-%Z).tar.gz"
 start=$(date '+%s')
 
 includes=(/srv/mail)
-includes+=(/ssl)
+includes+=(/certs)
 includes+=(/var/spool/postfix)
 includes+=(/var/spool/spamassassin)
 includes+=(/var/log)