Fix doc formatting

Closes gh-6275

Author: snicoll

spring-boot-docs/src/main/asciidoc/spring-boot-features.adoc

@@ -3557,6 +3557,7 @@ For instance, the following exposes another factory that uses a specific `Messag
 That you can use in any `@JmsListener`-annotated method as follows:
 
 [source,java,indent=0]
+[subs="verbatim,quotes"]
 ----
 	@Component
 	public class MyBean {
@@ -3692,6 +3693,7 @@ For instance, the following exposes another factory that uses a specific `Messag
 That you can use in any `@RabbitListener`-annotated method as follows:
 
 [source,java,indent=0]
+[subs="verbatim,quotes"]
 ----
 	@Component
 	public class MyBean {