LP#1774448 Auth poll spam/timing repairs

LP#1774448 Auth poll spam/timing repairs

Avoid spamming the server with authentication session checks on bad poll
time values.  Specifically, never poll more often than once per minute
and avoid integer overflow on long authentication timeout values
(greater than about 24.8 days) resulting in the poll running with an
effective timeout of zero and spamming the server with API calls.

Signed-off-by: Bill Erickson <berickxx@gmail.com>