message: fix esp32 fatal, disabled async
diff: @@ -994,10 +994,14 @@ bool WiFiManager::WiFi_scanNetworks(bool force,bool async){
  int8_t res;
  unsigned int _scanstart = millis();
  if(async){
  + #ifdef ESP8266
  using namespace std::placeholders; // for `_1`
  WiFi.scanNetworksAsync(std::bind(&WiFiManager::WiFi_scanComplete,this,_1));
  DEBUG_WM(DEBUG_VERBOSE,F("WiFi Scan ASYNC started"));
  return false;
  + #else
  + res = WiFi.scanNetworks();
  + #endif
  }
  else{
  res = WiFi.scanNetworks();
  