fix thread safety issue of ConsumerConfigurationListener (#15707)

Author: zrlw

dubbo-registry/dubbo-registry-api/src/main/java/org/apache/dubbo/registry/client/ServiceDiscoveryRegistryDirectory.java

@@ -65,6 +65,7 @@
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
+import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.stream.Collectors;
 
 import static org.apache.dubbo.common.constants.CommonConstants.APPLICATION_KEY;
@@ -711,7 +712,7 @@ protected void notifyOverrides() {
     }
 
     private static class ConsumerConfigurationListener extends AbstractConfiguratorListener {
-        private final List<ServiceDiscoveryRegistryDirectory<?>> listeners = new ArrayList<>();
+        private final List<ServiceDiscoveryRegistryDirectory<?>> listeners = new CopyOnWriteArrayList<>();
 
         ConsumerConfigurationListener(ModuleModel moduleModel) {
             super(moduleModel);