fixed problem with init redis server

[Mirocow]

fixed problem with init redis server if redis server don`t run
because @stream_socket_client return false (line https://github.com/yiisoft/yii2-redis/blob/master/Connection.php#L263)

[Mirocow]

it`s fixed php 5.6
работу проверял на php 5.6

[Mirocow]

$ php -v
PHP 5.6.14 (cli) (built: Oct 3 2015 14:43:37)
Copyright (c) 1997-2015 The PHP Group
Zend Engine v2.6.0, Copyright (c) 1998-2015 Zend Technologies
with Xdebug v2.3.3, Copyright (c) 2002-2015, by Derick Rethans

[samdark]

Thanks!