Remove EXTRA_ARGS from uwb-mqtt-publisher service ExecStart

- Empty EXTRA_ARGS causes systemd to add trailing space/argument
- This triggers 'unrecognized arguments' error
- Removing ${EXTRA_ARGS} fixes service startup
- Service now runs successfully

Author: Alex J Lennon

recipes-connectivity/uwb-mqtt-publisher/files/uwb-mqtt-publisher.service

@@ -14,8 +14,7 @@ ExecStart=/usr/bin/uwb-mqtt-publisher ${UART_PORT} \
     --mqtt-broker ${MQTT_BROKER} \
     --mqtt-port ${MQTT_PORT} \
     --mqtt-topic ${MQTT_TOPIC} \
-    --mqtt-rate-limit ${MQTT_RATE_LIMIT} \
-    ${EXTRA_ARGS}
+    --mqtt-rate-limit ${MQTT_RATE_LIMIT}
 ExecReload=/bin/kill -HUP $MAINPID
 Restart=always
 RestartSec=10