feat(lwip): Add extra "sntp/sntp.h" to be same as esp-idf
feat(lwip): Add extra "sntp/sntp.h" to be same as esp-idf

espressif/ESP8266_RTOS_SDK,espressif/ESP8266_RTOS_SDK,espressif/ESP8266_RTOS_SDK,espressif/ESP8266_RTOS_SDK,espressif/ESP8266_RTOS_SDK