message: add string guards
diff: * @license MIT
  */
  +#ifndef _WM_STRINGS_H_
  +#define _WM_STRINGS_H_
  +
  #ifndef WIFI_MANAGER_OVERRIDE_STRINGS
  // !!! THIS DOES NOT WORK, you cannot define in a sketch, if anyone one knows how to order includes to be able to do this help!
  @@ -354,3 +357,5 @@ static wifi_country_t WM_COUNTRY_US{"US",1,11,WIFI_COUNTRY_POLICY_AUTO};
  static wifi_country_t WM_COUNTRY_CN{"CN",1,13,WIFI_COUNTRY_POLICY_AUTO};
  static wifi_country_t WM_COUNTRY_JP{"JP",1,14,WIFI_COUNTRY_POLICY_AUTO};
  #endif
  +
  +#endif
  \ No newline at end of file
  