Ensure pass consumer tag as string to bunny amqp (fixes 8.1 compatibility)

Author: snapshotpl

pkg/amqp-bunny/AmqpSubscriptionConsumer.php

@@ -88,7 +88,7 @@ public function subscribe(Consumer $consumer, callable $callback): void
         $frame = $this->context->getBunnyChannel()->consume(
             $bunnyCallback,
             $consumer->getQueue()->getQueueName(),
-            $consumer->getConsumerTag(),
+            $consumer->getConsumerTag() ?? '',
             (bool) ($consumer->getFlags() & InteropAmqpConsumer::FLAG_NOLOCAL),
             (bool) ($consumer->getFlags() & InteropAmqpConsumer::FLAG_NOACK),
             (bool) ($consumer->getFlags() & InteropAmqpConsumer::FLAG_EXCLUSIVE),