EventPublishingServiceDiscovery add error log (#8066)

* add error log

* commit

Co-authored-by: roshilikang <roshilikang@didiglobal.com>

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

@@ -284,6 +284,7 @@ protected final void executeWithEvents(Optional<? extends Event> beforeEvent,
         try {
             action.execute();
         } catch (Throwable e) {
+            logger.error("Execute action throws and dispatch a ServiceDiscoveryExceptionEvent.", e);
             dispatchEvent(new ServiceDiscoveryExceptionEvent(this, serviceDiscovery, e));
         }
         afterEvent.ifPresent(this::dispatchEvent);