Fix syntax error and redundant connection call in MQTT client

- Removed duplicate `async` keyword from `on_connect` method.
- Removed redundant `await client.connect()` to avoid double connection attempt.

dayglo_detector/dayglo_detector.py

@@ -33,7 +33,7 @@ initial_snapshot_processed = False
 connected_once = False
 
 class DaygloDetectorMQTTClient(MQTTClient):
-    async async def on_connect(self, client, flags, rc, properties):
+    async def on_connect(self, client, flags, rc, properties):
         global connected_once
         if rc == 0 and not connected_once:
             print("Connected successfully to MQTT broker")
@@ -133,7 +133,6 @@ async def main():
     client = DaygloDetectorMQTTClient("dayglo_detector")
     client.set_auth_credentials(MQTT_USERNAME, MQTT_PASSWORD)
 
-    await client.connect(MQTT_BROKER, MQTT_PORT, keepalive=60)
     await client.connect(MQTT_BROKER, MQTT_PORT, keepalive=60)
     await asyncio.get_event_loop().create_future()