message: Both infoids and _ap_password are intialized by check time.
  Comparing it to NULL raises operation overload.
diff: @@ -1904,7 +1904,7 @@ void WiFiManager::handleInfo() {
  #endif
  for(size_t i=0; i<infos;i++){
  - if(infoids[i] != NULL) page += getInfoData(infoids[i]);
  + if(!infoids[i].isEmpty()) page += getInfoData(infoids[i]);
  }
  page += F("</dl>");
  if(_showInfoUpdate){
  @@ -3227,7 +3227,7 @@ String WiFiManager::toStringIp(IPAddress ip) {
  boolean WiFiManager::validApPassword(){
  // check that ap password is valid, return false
  - if (_apPassword == NULL) _apPassword = "";
  + if (_apPassword.isEmpty()) _apPassword = "";
  if (_apPassword != "") {
  if (_apPassword.length() < 8 || _apPassword.length() > 63) {
  #ifdef WM_DEBUG_LEVEL
  