Email notification of expiring certificate does not include port

[kitserve]

We manage a few hosts that run more than one service on the same hostname, for example Apache and Dovecot. This sometimes results in the situation where the certificate has been updated and is fine on e.g. Apache, because it's frequently reloaded, but Dovecot hasn't been reloaded and is still using the previous certificate. When manually scanning the hosts on the command line, it's very easy to see which service is expiring as the port number is shown. However the email version (which we rely on for automated notifications via cron) just includes the generic text "The SSL certificate for example.com "(CN: example.com)" will expire on May 26 16:53:23 2022 GMT". It would make our lives easier if we could see at a glance from the email which service needs reloading.