[Host.Serialization] Introduce multi-targeting for net8, net6 and net…

…standard #211

Signed-off-by: Tomasz Maruszak <[email protected]>

src/SlimMessageBus.Host.Kafka/KafkaMessageBus.cs

@@ -154,7 +154,7 @@ protected override async Task ProduceToTransport(object message, string path, by
         var deliveryResult = await task.ConfigureAwait(false);
         if (deliveryResult.Status == PersistenceStatus.NotPersisted)
         {
-            throw new ProducerMessageBusException($"Error while publish message {message} of type {messageType.Name} to topic {path}. Kafka persistence status: {deliveryResult.Status}");
+            throw new ProducerMessageBusException($"Error while publish message {message} of type {messageType?.Name} to topic {path}. Kafka persistence status: {deliveryResult.Status}");
         }
 
         // log some debug information