### Environment

* Dubbo version: 3.0

### Steps to reproduce this issue
翻看github构建日志本来是去找GenericServiceTest为啥常常出现java.lang.IllegalStateException: Failed to check the status of the service org.apache.dubbo.config.spring.api.LocalMissClass的线索，相关的线索没找到，却找到了这个
2021-09-04T20:19:48.3933128Z [04/09/21 20:19:47:427 UTC] main  WARN integration.RegistryProtocol:  [DUBBO] unsubscribe listener == null, dubbo version: 3.0.3-SNAPSHOT, current host: 172.17.16.1
2021-09-04T20:19:48.3934495Z java.lang.IllegalArgumentException: unsubscribe listener == null
2021-09-04T20:19:48.3936385Z 	at org.apache.dubbo.registry.support.AbstractRegistry.unsubscribe(AbstractRegistry.java:329)
2021-09-04T20:19:48.3938947Z 	at org.apache.dubbo.registry.support.FailbackRegistry.unsubscribe(FailbackRegistry.java:328)
2021-09-04T20:19:48.3942540Z 	at org.apache.dubbo.registry.ListenerRegistryWrapper.unsubscribe(ListenerRegistryWrapper.java:134)
2021-09-04T20:19:48.3945186Z 	at org.apache.dubbo.registry.integration.RegistryProtocol$ExporterChangeableWrapper.unexport(RegistryProtocol.java:876)
2021-09-04T20:19:48.3948433Z 	at org.apache.dubbo.registry.integration.RegistryProtocol$DestroyableExporter.unexport(RegistryProtocol.java:669)
2021-09-04T20:19:48.3950662Z 	at org.apache.dubbo.config.ServiceConfig.unexport(ServiceConfig.java:187)
2021-09-04T20:19:48.3952706Z 	at org.apache.dubbo.config.bootstrap.DubboBootstrap.lambda$unexportServices$9(DubboBootstrap.java:1487)
2021-09-04T20:19:48.3954404Z 	at java.base/java.util.ArrayList.forEach(ArrayList.java:1541)
2021-09-04T20:19:48.3956255Z 	at org.apache.dubbo.config.bootstrap.DubboBootstrap.unexportServices(DubboBootstrap.java:1484)
2021-09-04T20:19:48.3958714Z 	at org.apache.dubbo.config.bootstrap.DubboBootstrap.destroy(DubboBootstrap.java:1635)
2021-09-04T20:19:48.3960885Z 	at org.apache.dubbo.config.bootstrap.DubboBootstrap.reset(DubboBootstrap.java:239)
2021-09-04T20:19:48.3963018Z 	at org.apache.dubbo.config.bootstrap.DubboBootstrap.reset(DubboBootstrap.java:225)
2021-09-04T20:19:48.3965492Z 	at org.apache.dubbo.config.spring.schema.GenericServiceTest.tearDown(GenericServiceTest.java:67)
并且不止这一个测试类抛这个异常，有十多个测试类都抛这个东西，看了看代码，感觉应该是重复注销导致的，RegistryProtocol注销listener前检查一下是否为null应该就能避免这个异常了。
public void setExporter(Exporter<T> exporter) {
            this.exporter = exporter;
        }
        @Override
        public void unexport() {
            String key = getCacheKey(this.originInvoker);
            bounds.remove(key);
            Registry registry = RegistryProtocol.this.getRegistry(getRegistryUrl(originInvoker));
            try {
                registry.unregister(registerUrl);
            } catch (Throwable t) {
                logger.warn(t.getMessage(), t);
            }
            try {
                if (subscribeUrl != null) {
                    Map<URL, NotifyListener> overrideListeners = getProviderConfigurationListener(subscribeUrl).getOverrideListeners();
                    NotifyListener listener = overrideListeners.remove(registerUrl);
                    if (listener != null) {
                        registry.unsubscribe(subscribeUrl, listener);
                        ApplicationModel applicationModel = getApplicationModel(registerUrl.getScopeModel());
                        if (applicationModel.getModelEnvironment().getConfiguration().convert(Boolean.class, ENABLE_CONFIGURATION_LISTEN, true)) {
                            for (ModuleModel moduleModel : applicationModel.getPubModuleModels()) {
                                if (moduleModel.getServiceRepository().getExportedServices().size() > 0) {
                                    moduleModel.getExtensionLoader(GovernanceRuleRepository.class).getDefaultExtension()
                                        .removeListener(subscribeUrl.getServiceKey() + CONFIGURATORS_SUFFIX,
                                            serviceConfigurationListeners.remove(subscribeUrl.getServiceKey()));
                                }
                            }
                        }
                    }