esp32s2: don't delete the event loop

[jepler]

.. it seems to make the esp-idf grumpy.

[jepler]

This was to avoid an error in debug builds but the cure is worse than the disease.

esp_err_t esp_event_loop_create_default(void)
{
    if (s_default_loop) {
        return ESP_ERR_INVALID_STATE;
    }

[tannewt]

How about tracking if netif has been started once and only get the loop when it hasn't been?

[tannewt]

Thank you!