Notice (8): Undefined index: HTTP_X_FORWARDED_PROTO [APP/Controller/PagesController.php, line 51]

    {
        if($_SERVER['HTTP_X_FORWARDED_PROTO']=="http"){
            $redirect = 'https://' . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'];

App\Controller\PagesController::initialize() - APP/Controller/PagesController.php, line 51
Cake\Controller\Controller::__construct() - CORE/src/Controller/Controller.php, line 272
ReflectionClass::newInstance() - [internal], line ??
Cake\Http\ControllerFactory::create() - CORE/src/Http/ControllerFactory.php, line 47
Cake\Http\ActionDispatcher::dispatch() - CORE/src/Http/ActionDispatcher.php, line 91
Cake\Http\BaseApplication::__invoke() - CORE/src/Http/BaseApplication.php, line 234
Cake\Http\Runner::__invoke() - CORE/src/Http/Runner.php, line 65
Cake\Routing\Middleware\RoutingMiddleware::__invoke() - CORE/src/Routing/Middleware/RoutingMiddleware.php, line 162
Cake\Http\Runner::__invoke() - CORE/src/Http/Runner.php, line 65
Cake\Routing\Middleware\AssetMiddleware::__invoke() - CORE/src/Routing/Middleware/AssetMiddleware.php, line 88
Cake\Http\Runner::__invoke() - CORE/src/Http/Runner.php, line 65
Cake\Error\Middleware\ErrorHandlerMiddleware::__invoke() - CORE/src/Error/Middleware/ErrorHandlerMiddleware.php, line 96
Cake\Http\Runner::__invoke() - CORE/src/Http/Runner.php, line 65
Cake\Http\Runner::run() - CORE/src/Http/Runner.php, line 51
Cake\Http\Server::run() - CORE/src/Http/Server.php, line 97
[main] - ROOT/webroot/index.php, line 40