Polish "Fix handling of JMS listener concurrency properties"

See spring-projectsgh-37180

Author: wilkinsona

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/jms/JmsProperties.java

@@ -146,7 +146,8 @@ public static class Listener {
 		private AcknowledgeMode acknowledgeMode;
 
 		/**
-		 * Minimum number of concurrent consumers.
+		 * Minimum number of concurrent consumers. When max-concurrency is not specified
+		 * the minimum will also be used as the maximum.
 		 */
 		private Integer concurrency;