Fix blacklist unknown number mode query string.

The same was string was being used to query the database for both private and
unknown numbers, with the effect that enabling private number blocking also
blocked unknown numbers.

Change-Id: I5a77566fde3187ff6044415c64e74ce4e10cd4dc
Improved the minimum amount of time that must have elapsed for change the rotation

Change-Id: I36f27727bbd5d6d7a192ffb9222223ecda2be0eb