message: Use esp_wifi_set_country_code for ESP32
  Replaces the use of esp_wifi_set_country() with esp_wifi_set_country_code() for ESP32 in order to both solve a crash under Arduino 2.x and remove the requirement to independently maintain country-specific channel settings
diff: @@ -3450,16 +3450,19 @@ bool WiFiManager::WiFiSetCountry(){
  if(WiFi.getMode() == WIFI_MODE_NULL){
  DEBUG_WM(DEBUG_ERROR,"[ERROR] cannot set country, wifi not init");
  } // exception if wifi not init!
  - else if(_wificountry == "US") err = esp_wifi_set_country(&WM_COUNTRY_US);
  - else if(_wificountry == "JP") err = esp_wifi_set_country(&WM_COUNTRY_JP);
  - else if(_wificountry == "CN") err = esp_wifi_set_country(&WM_COUNTRY_CN);
  + // Assumes that _wificountry is set to one of the supported country codes : "01"(world safe mode) "AT","AU","BE","BG","BR",
  + // "CA","CH","CN","CY","CZ","DE","DK","EE","ES","FI","FR","GB","GR","HK","HR","HU",
  + // "IE","IN","IS","IT","JP","KR","LI","LT","LU","LV","MT","MX","NL","NO","NZ","PL","PT",
  + // "RO","SE","SI","SK","TW","US"
  + // If an invalid country code is passed, ESP_ERR_WIFI_ARG will be returned
  + // This also uses 802.11d mode, which matches the STA to the country code of the AP it connects to (meaning
  + // that the country code will be overridden if connecting to a "foreign" AP)
  + else err = esp_wifi_set_country_code(_wificountry.c_str(), true);
  +
  #ifdef WM_DEBUG_LEVEL
  - else{
  - DEBUG_WM(DEBUG_ERROR,"[ERROR] country code not found");
  - }
  if(err){
  if(err == ESP_ERR_WIFI_NOT_INIT) DEBUG_WM(DEBUG_ERROR,"[ERROR] ESP_ERR_WIFI_NOT_INIT");
  - else if(err == ESP_ERR_INVALID_ARG) DEBUG_WM(DEBUG_ERROR,"[ERROR] ESP_ERR_WIFI_ARG");
  + else if(err == ESP_ERR_INVALID_ARG) DEBUG_WM(DEBUG_ERROR,"[ERROR] ESP_ERR_WIFI_ARG (invalid country code)");
  else if(err != ESP_OK)DEBUG_WM(DEBUG_ERROR,"[ERROR] unknown error",(String)err);
  }
  #endif
  