老师，您好，我现在遇到了一个问题，就是在5-5章节中，引入nacos的依赖，然后启动的话就会报错：

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'connManFactory' defined in class path resource [org/springframework/cloud/commons/httpclient/HttpClientConfiguration$ApacheHttpClientConfiguration.class]: Post-processing of merged bean definition failed; nested exception is java.lang.IllegalStateException: Failed to introspect Class [org.springframework.cloud.commons.httpclient.DefaultApacheHttpClientConnectionManagerFactory] from ClassLoader [sun.misc.Launcher$AppClassLoader@18b4aac2]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:570) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:845) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:877) ~[spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549) ~[spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:141) ~[spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:743) [spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:390) [spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:312) [spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1214) [spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1203) [spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE]
	at com.itmuch.usercenter.UserCenterApplication.main(UserCenterApplication.java:13) [classes/:na]
Caused by: java.lang.IllegalStateException: Failed to introspect Class [org.springframework.cloud.commons.httpclient.DefaultApacheHttpClientConnectionManagerFactory] from ClassLoader [sun.misc.Launcher$AppClassLoader@18b4aac2]
	at org.springframework.util.ReflectionUtils.getDeclaredMethods(ReflectionUtils.java:507) ~[spring-core-5.1.9.RELEASE.jar:5.1.9.RELEASE]
	at org.springframework.util.ReflectionUtils.doWithLocalMethods(ReflectionUtils.java:367) ~[spring-core-5.1.9.RELEASE.jar:5.1.9.RELEASE]
	at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.buildLifecycleMetadata(InitDestroyAnnotationBeanPostProcessor.java:207) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
	at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.findLifecycleMetadata(InitDestroyAnnotationBeanPostProcessor.java:189) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
	at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.postProcessMergedBeanDefinition(InitDestroyAnnotationBeanPostProcessor.java:128) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
	at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.postProcessMergedBeanDefinition(CommonAnnotationBeanPostProcessor.java:297) ~[spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyMergedBeanDefinitionPostProcessors(AbstractAutowireCapableBeanFactory.java:1077) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:567) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
	... 15 common frames omitted
Caused by: java.lang.NoClassDefFoundError: org/apache/http/config/RegistryBuilder
	at java.lang.Class.getDeclaredMethods0(Native Method) ~[na:1.8.0_191]
	at java.lang.Class.privateGetDeclaredMethods(Class.java:2701) ~[na:1.8.0_191]
	at java.lang.Class.getDeclaredMethods(Class.java:1975) ~[na:1.8.0_191]
	at org.springframework.util.ReflectionUtils.getDeclaredMethods(ReflectionUtils.java:489) ~[spring-core-5.1.9.RELEASE.jar:5.1.9.RELEASE]
	... 22 common frames omitted
Caused by: java.lang.ClassNotFoundException: org.apache.http.config.RegistryBuilder
	at java.net.URLClassLoader.findClass(URLClassLoader.java:382) ~[na:1.8.0_191]
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[na:1.8.0_191]
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349) ~[na:1.8.0_191]
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[na:1.8.0_191]
	... 26 common frames omitted