Fix description of brokerUrl property in ArtemisProperties

Update description to refer to url instead of port.

See gh-37260

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

@@ -44,7 +44,7 @@ public class ArtemisProperties {
 	private ArtemisMode mode;
 
 	/**
-	 * Artemis broker port.
+	 * Artemis broker url.
 	 */
 	private String brokerUrl;