message: Fix default implementation method for new ErrorHandler
diff: @@ -51,7 +51,7 @@ public:
  * @param error - &std::exception;.
  * @return - std::shared_ptr to &id:oatpp::web::protocol::http::outgoing::Response;.
  */
  - virtual std::shared_ptr<protocol::http::outgoing::Response> handleError(const std::exception_ptr& exceptionPtr) = 0;
  + virtual std::shared_ptr<protocol::http::outgoing::Response> handleError(const std::exception_ptr& exceptionPtr);
  /**
  * Implement this method!
  