[cinder] meeting time reminder

For people who were on Daylight Savings Time but now are not, just a reminder that this week's Cinder meeting at 16:00 UTC may be an hour earlier for you.

The meeting-time-change-poll link will be in a separate email. If the time is changed, it will be effective for the first meeting in December (4 December 2019). That's because we'll be having the Virtual PTG during the last week of November (that poll will be out shortly).

cheers, brian