Laravel 5.1 - Predis错误抛出Apple推送通知的异常

Question

I has been applied predis/predis 1.1.1 with redis-server in my project.
I tried to turn off redis-server to handle redis error

use Predis\CommunicationException;

try {
    // to do sth
} catch (CommunicationException $e) {
    // throw exception
}

But errors was not caught, laravel.log display below lines:

exception 'ZendService\Apple\Exception\StreamSocketClientException' with message 'stream_socket_client(): unable to connect to tcp://127.0.0.1:6379 (Connection refused)' in /var/app/current/vendor/predis/predis/src/Connection/StreamConnection.php:127
Stack trace:
#0 [internal function]: ZendService\Apple\Apns\Client\AbstractClient->ZendService\Apple\Apns\Client\{closure}(2, 'stream_socket_c...', '/var/app/curren...', 127, Array)
#1 /var/app/current/vendor/predis/predis/src/Connection/StreamConnection.php(127): stream_socket_client('tcp://127.0.0.1...', 111, 'Connection refu...', 0.15, 4)
#2 /var/app/current/vendor/predis/predis/src/Connection/StreamConnection.php(178): Predis\Connection\StreamConnection->createStreamSocket(Object(Predis\Connection\Parameters), 'tcp://127.0.0.1...', 4)
#3 /var/app/current/vendor/predis/predis/src/Connection/StreamConnection.php(100): 

My composer.json

"require": {
    "php": ">=5.5.9",
    "ext-oauth": "*",
    "laravel/framework": "5.1.*",
    "lucadegasperi/oauth2-server-laravel": "dev-mac-token-support",
    "guzzlehttp/guzzle": "6.2.3",
    "intervention/image": "2.*",
    "league/csv": "7.*",
    "davibennun/laravel-push-notification": "dev-laravel5",
    "stripe/stripe-php": "^3.14",
    "jenssegers/rollbar": "~1.5",
    "sammyk/laravel-facebook-sdk": "^3.0",
    "mandrill/mandrill": "^1.0",
    "pusher/pusher-php-server": "~2.0",
    "phpmailer/phpmailer": "~6.0",
    "predis/predis": "1.1.1"
},

Why instance of StreamSocketClientException was thrown?