wificfg: lock the lwip tcp core when initializing mdns.
wificfg: lock the lwip tcp core when initializing mdns.

ourairquality/esp-open-rtos,ourairquality/esp-open-rtos,ourairquality/esp-open-rtos,ourairquality/esp-open-rtos,ourairquality/esp-open-rtos,ourairquality/esp-open-rtos