20613: Update unconfigured logger check to accommodate NullHandler

20613: Update unconfigured logger check to accommodate NullHandler

googleapiclient sets up its own NullHandler, as recommended by the
logging documentation. That makes the hasHandlers() test not work as
intended, so instead we traverse the hierarchy ourselves looking for a
real handler.

Arvados-DCO-1.1-Signed-off-by: Brett Smith <brett.smith@curii.com>