Use two queues for concurrent t_otp.py daemons

Use two queues for concurrent t_otp.py daemons

t_otp.py occasionally fails during the #8708 regression test, reading
a true answer instead of the expected false answer during the first
verify() call.  Most likely the daemons are writing their answers to
the shared queue out of order.  Use a separate queue for the second
daemon to ensure correct correlation of results.