mqtt_client.py: connect to mixer on demand

mqtt_client.py

@@ -13,7 +13,7 @@ class MqttClient:
     MQTT_COMMAND_TOPIC = "livingroom/voc/allen_heath_qu16_mixer"
 
     def __init__(self, mixer_ip):
-        self.mixer = Mixer(mixer_ip)
+        self.mixer_ip = mixer_ip
         self.client = mqtt.Client(callback_api_version=mqtt.CallbackAPIVersion.VERSION2)
 
     def mqtt_autodiscovery(self):
@@ -48,11 +48,13 @@ class MqttClient:
 
         j = json.loads(payload)
 
+        mixer = Mixer(self.mixer_ip)
+
         match j["command"]:
             case "scene_recall":
-                self.mixer.scene_recall(j["args"]["scene_id"])
+                mixer.scene_recall(j["args"]["scene_id"])
             case "shutdown":
-                self.mixer.shutdown()
+                mixer.shutdown()
 
     def run(self, hostname):
         self.client.on_connect = self.on_connect