SMTP port

[arist0v]

as discuss in this thread: https://discourse.mozilla.org/t/mozilla-webthings-registration-server/95025/20

it would be nice to have the option to specify the smtp port not just use 25 so we could use gmail as e-mail senders.

[benfrancis]

Thanks for this suggestion.

Note: As discussed in https://discourse.mozilla.org/t/mozilla-webthings-registration-server/95025/27?u=bfrancis this shouldn't be needed for smtp.gmail.com, only SMTP servers using a non-default port.

[arist0v]

in the topics, you'll find the link to the rust modification to do!