Reminder: remove calendar stored credentials when switching HVAC modes

If you've just switched from heating to cooling (or the other way around for those down under), the first run of the system will use the calendar credentials stored by Google calendar client library in ${HOME}/.dz/calendar/StoredCredential, and your system will try to use the wrong schedule (that is, if you followed our advice and are using two different calendars for heating and cooling).

Just move that file away, or remove it altogether - DZ will present the credentials screen next time the calendar needs to be consulted.