Adds property to disable RouteRefreshListener

Fixes gh-2958

spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/config/GatewayAutoConfiguration.java

@@ -264,6 +264,7 @@ public class GatewayAutoConfiguration {
 
 	@Bean
 	@ConditionalOnClass(name = "org.springframework.cloud.client.discovery.event.HeartbeatMonitor")
+	@ConditionalOnProperty(prefix = GatewayProperties.PREFIX, name = ".route-refresh-listener.enabled", matchIfMissing = true)
 	public RouteRefreshListener routeRefreshListener(ApplicationEventPublisher publisher) {
 		return new RouteRefreshListener(publisher);
 	}

spring-cloud-gateway-server/src/main/resources/META-INF/additional-spring-configuration-metadata.json

@@ -424,6 +424,12 @@
       "type": "java.lang.Boolean",
       "description": "Include the port in matching the host name.",
       "defaultValue": "true"
+    },
+    {
+      "name": "spring.cloud.gateway.route-refresh-listener.enabled",
+      "type": "java.lang.Boolean",
+      "description": "If RouteRefreshListener should be turned on.",
+      "defaultValue": "true"
     }
   ]
 }