Update redis.md

Fixed example of configuration.
Current expression is `in_array('phpredis', $this->config['scheme_extensions'], true)` (https://github.com/php-enqueue/redis/blob/0.9.6/RedisConnectionFactory.php#L99)

Author: Anton

Diff for: docs/transport/redis.md

@@ -71,7 +71,7 @@ $factory = new RedisConnectionFactory([]);
 $factory = new RedisConnectionFactory([
     'host' => 'example.com',
     'port' => 1000,
-    'vendor' => 'phpredis',
+    'scheme_extensions' => ['phpredis'],
 ]);
 
 // same as above but given as DSN string
@@ -101,7 +101,7 @@ use Enqueue\Redis\RedisConnectionFactory;
 $connectionFactory = new RedisConnectionFactory([
     'host' => 'localhost',
     'port' => 6379,
-    'scheme_extensions' => 'predis',
+    'scheme_extensions' => ['predis'],
 ]);
 
 $context = $connectionFactory->createContext();
@@ -232,4 +232,4 @@ To use it with Enqueue Redis you have to pass REDIS_URL to RedisConnectionFactor
 $connection = new \Enqueue\Redis\RedisConnectionFactory(getenv('REDIS_URL'));
 ```
 
-[back to index](../index.md)
+[back to index](../index.md)