stop execution when unauthenticated, to prevent the page to show when…

… canceling auth popup

lib/Cake/Controller/Component/Auth/BasicAuthenticate.php

@@ -117,9 +117,9 @@ public function getUser(CakeRequest $request) {
  * @return boolean True
  */
 	public function unauthenticated(CakeRequest $request, CakeResponse $response) {
-		$response->header($this->loginHeaders());
-		$response->statusCode(401);
-		$response->send();
+		$Exception = new UnauthorizedException();
+		$Exception->responseHeader($this->loginHeaders());
+		throw $Exception;
 		return true;
 	}