Fix doc typo

Author: garyrussell

src/reference/asciidoc/kafka.adoc

@@ -659,7 +659,7 @@ When you use this setting, we recommend that you set the template's `sharedReply
 IMPORTANT: If you have multiple client instances and you do not configure them as discussed in the preceding paragraph, each instance needs a dedicated reply topic.
 An alternative is to set the `KafkaHeaders.REPLY_PARTITION` and use a dedicated partition for each instance.
 The `Header` contains a four-byte int (big-endian).
-The server must use this header to route the reply to the correct topic (`@KafkaListener` does this).
+The server must use this header to route the reply to the correct partition (`@KafkaListener` does this).
 In this case, though, the reply container must not use Kafka's group management feature and must be configured to listen on a fixed partition (by using a `TopicPartitionOffset` in its `ContainerProperties` constructor).
 
 NOTE: The `DefaultKafkaHeaderMapper` requires Jackson to be on the classpath (for the `@KafkaListener`).