fixed fatal error and few typos

few typos, and one fatal error fixed

```
Fatal error: Call to a member function send_channel_method_frame() on a non-object in PhpAmqpLib/Channel/AbstractChannel.php on line 169

Call Stack:
    0.2686    7151600   1. Tester\Environment::handleException(class PhpAmqpLib\Exception\AMQPProtocolChannelException) /vendor/nette/tester/Tester/Framework/Environment.php:0
    0.2688    7152320   2. Kdyby\RabbitMq\AmqpMember->__destruct() src/Kdyby/RabbitMq/AmqpMember.php:0
    0.2688    7152432   3. PhpAmqpLib\Channel\AMQPChannel->close(???, ???, ???) src/Kdyby/RabbitMq/AmqpMember.php:113
    0.2689    7154384   4. PhpAmqpLib\Channel\AbstractChannel->send_method_frame(array(2), class PhpAmqpLib\Wire\AMQPWriter) PhpAmqpLib/Channel/AMQPChannel.php:161
```