No such extension org.apache.dubbo.registry.RegistryFactory by name dubbo, no related exception was found, please check whether related SPI module is missing.

- [x] I have searched the [issues](https://github.com/apache/dubbo-admin/issues) of this repository and believe that this is not a duplicate.
- [x] I have checked the [REAMDE](https://github.com/apache/dubbo-admin/blob/develop/README.md) of this repository and believe that this is not a duplicate.

### Environment

* Dubbo Admin version: 0.4.0
* Registry center detail (type and version): zookeeper 3.8.0
* Operating System version: centos8
* Java version: openjdk version "1.8.0_312"

### Steps to reproduce this issue

**1. mvn --projects dubbo-admin-server spring-boot:run -e的时候报错，报错信息**
```
Caused by: java.lang.IllegalStateException: No such extension org.apache.dubbo.registry.RegistryFactory by name dubbo, no related exception was found, please check whether related SPI module is missing.
```

**2. dubbo-admin/dubbo-admin-server/src/main/resources/application.properties配置如下：**
```
#centers in dubbo2.7, if you want to add parameters, please add them to the url

#admin.registry.address=zookeeper://127.0.0.1:2181

admin.config-center=zookeeper://172.18.0.2:12181

#admin.metadata-report.address=zookeeper://127.0.0.1:2181
```
*172.18.0.2:12181，这是因为zookeeper安装在另一个docker上了，所以额外设置了zookeeper的端口为12181*

通过zooInspector，设置了dubbo/config/dubbo/dubbo.properties，具体配置如下
`
dubbo.registry.address=zookeeper://172.18.0.2:12181
dubbo.metadata-report.address=zookeeper://172.18.0.2:12181
`

dubbo-admin/pom.xml文件，
`3.0.8`

**3. 根据dubbo-admin的README操作，mvn clean package -Dmaven.test.skip=true编译是正常的；**

### Expected Result

预期启动成功，启动dubbo-provider后，dubbo-admin页面能查询到服务提供者，且元数据处不显示“无元数据信息”

### Actual Result

build成功后，start失败

Start with dubbo-admin-server/src/main/resources/application.properties and the dubbo-version in pom.xml, then run the reported `mvn --projects dubbo-admin-server spring-boot:run -e` command. Trace the startup configuration around the RegistryFactory error and verify the configured ZooKeeper addresses; done means the server starts, a provider is visible in the admin page, and metadata is displayed.

Written by the indexing model from the issue text.