Allow multiple vcc api keys (#85)

* Multiple vccapikeys function

* Reduce api calls for key checks

* Change sleeptime

* Optimize logging

* Format log datetime

* Change default conf

* Set device offline, if no working vcc api key can be found

* Fix climate scheduler

* Only redact sensitive data if debug is enabled

src/mqtt.py

@@ -352,3 +352,8 @@ def create_ha_devices():
 
 def send_heartbeat():
     mqtt_client.publish(availability_topic, "online")
+
+
+def send_offline():
+    mqtt_client.publish(availability_topic, "offline")
+