Wifi managers improvements (#503)

* Add parameters to wifi manager: gateway name and base topic
Enable to restart the ESP and erase the parameters by MQTT

main/config_ADC.h

@@ -30,7 +30,7 @@ extern void setupADC();
 extern void ADCtoMQTT();
 /*----------------------------USER PARAMETERS-----------------------------*/
 /*-------------DEFINE YOUR MQTT PARAMETERS BELOW----------------*/
-#define ADCTOPIC  Base_Topic Gateway_Name "/ADCtoMQTT"
+#define ADCTOPIC  "/ADCtoMQTT"
 #define TimeBetweenReadingADC 500 // time between 2 ADC readings, minimum 200 to let the time of the ESP to keep the connection
 #define ThresholdReadingADC 50  //  following the comparison between the previous value and the current one +- the threshold the value will be published or not