remove option for RX_PULLUP, this is enabled by default in esp-idf

Author: Pelle van der Heide

src/uart/emsuart_esp32.cpp

@@ -92,9 +92,6 @@ void EMSuart::start(const uint8_t tx_mode, const uint8_t rx_gpio, const uint8_t
         uart_param_config(EMSUART_NUM, &uart_config);
         uart_set_pin(EMSUART_NUM, tx_gpio, rx_gpio, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE);
         uart_set_line_inverse(EMSUART_NUM, inverse_mask);
-#if defined(EMSUART_RX_PULLUP)
-        gpio_set_pull_mode(gpio_num_t(rx_gpio), GPIO_PULLUP_ONLY);
-#endif
         uart_driver_install(EMSUART_NUM, 129, 0, (EMS_MAXBUFFERSIZE + 1) * 2, &uart_queue, 0); // buffer must be > fifo
         uart_set_rx_full_threshold(EMSUART_NUM, 1);
         uart_set_rx_timeout(EMSUART_NUM, 0); // disable