Use SIGINT signal for podman stop.

Dockerfile

@@ -9,4 +9,5 @@ WORKDIR /root
 COPY thermostat.py /root/
 COPY entrypoint.sh /root/
 ENV FLASK_APP thermostat.py
+STOPSIGNAL SIGINT
 ENTRYPOINT ["/root/entrypoint.sh"]

thermostat.py

@@ -381,10 +381,8 @@ def thermostat_loop():
             else:
               logging.debug("Relay already off.")
     time.sleep(load_shedder_interval)
+  logging.info("====== Ended successfully ======")
 
 t1 = Thread(target=thermostat_loop)
 t1.daemon = True
 t1.start()
-
-dbconn.close()
-logging.info("====== Ended successfully ======")