Add cc contacts, wait promises, add SMTP URL

Send emails to the CC_CONTACTS as well when noticing offline validators.

Previously the promises were pushed correctly with a setTimeout in
sendNoticeEmails in email.js. However since setTimeout does not return a
Promise, the Promise.all() was not receiving an array of Promises and
was resolving instantly. Now push promises into the promises array so
that it will resolve once all mails are sent and we can log successful
execution.

Also added gwdg STMP URL. email.gwdg.de Exchange server does not work on the server
bloxberg-cloud.mpdl.mpg.de. Use mailer.gwdg.de Exim (Unix) mail server.