support ak/sk authentication when using serverAddr

spring-cloud-alibaba-starters/spring-cloud-alibaba-sentinel-datasource/src/main/java/com/alibaba/cloud/sentinel/datasource/factorybean/NacosDataSourceFactoryBean.java

@@ -60,9 +60,14 @@ public class NacosDataSourceFactoryBean implements FactoryBean<NacosDataSource>
 			properties.setProperty(PropertyKeyConst.SERVER_ADDR, this.serverAddr);
 		}
 		else {
+			properties.setProperty(PropertyKeyConst.ENDPOINT, this.endpoint);
+		}
+
+		if (!StringUtils.isEmpty(this.accessKey)) {
 			properties.setProperty(PropertyKeyConst.ACCESS_KEY, this.accessKey);
+		}
+		if (!StringUtils.isEmpty(this.secretKey)) {
 			properties.setProperty(PropertyKeyConst.SECRET_KEY, this.secretKey);
-			properties.setProperty(PropertyKeyConst.ENDPOINT, this.endpoint);
 		}
 		if (!StringUtils.isEmpty(this.namespace)) {
 			properties.setProperty(PropertyKeyConst.NAMESPACE, this.namespace);