Revert constant in Javadoc

Co-authored-by: Gary Russell <grussell@vmware.com>

Author: artembilan

spring-integration-core/src/main/java/org/springframework/integration/store/AbstractKeyValueMessageStore.java

@@ -60,7 +60,7 @@ protected AbstractKeyValueMessageStore() {
 	 * Construct an instance based on the provided prefix for keys to distinguish between
 	 * different store instances in the same target key-value database. Defaults to an
 	 * empty string - no prefix. The actual prefix for messages is
-	 * {@code prefix + MESSAGE_}; for message groups - {@code prefix + GROUP_OF_MESSAGES_}
+	 * {@code prefix + MESSAGE_}; for message groups - {@code prefix + MESSAGE_GROUP_}
 	 * @param prefix the prefix to use
 	 * @since 4.3.12
 	 */