[AIRFLOW-5073] Change SQLSensor to optionally treat NULL as keep poking (#6336)
[AIRFLOW-5073] Change SQLSensor to optionally treat NULL as keep poking (#6336)

(cherry picked from commit 6ba54422225a11bcdf165e861ec7a9335ca5485c)

owlabs/incubator-airflow,owlabs/incubator-airflow,owlabs/incubator-airflow,owlabs/incubator-airflow