Description:
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It crashes on next iteration after created fork process by pcntl_fork()

Test script:
---------------
<?php
$connection = new AMQPConnection();$connection->connect();
$channel = new AMQPChannel($connection);
$q = new AMQPQueue($channel);$q->setName('queue.hello');$q->declare();
while (true) {
	$msg = $q->get(AMQP_NOPARAM); // It will crush on second iteration
	sleep(2);
	if ($msg) {
		echo $msg->getBody() . "\n";
		$q->ack($msg->getDeliveryTag());
	}

	switch ($pid = pcntl_fork()) {
		case -1: // Fail
			die("Cant create fork process");

		case 0:
			echo "New process \n";
			exit; // The end of the forked process

		default:
			pcntl_wait($status, WNOHANG); //Protects against Zombie children
			break;
	}
}
$connection->disconnect(); // disconnect

Expected result:
----------------
It some times freeze and lost Channel but not the connection.
But usually throw PHP Fatal error:  Uncaught exception 'AMQPQueueException' with 
message 'Unknown server error occurred.'