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

### Environment

* Dubbo version: 2.7.4.1
* Java version: 1.8

### Actual Result

[https://github.com/apache/dubbo/blob/839d2a604e629ea9e96b964be09ae221e85312ba/dubbo-common/src/main/java/org/apache/dubbo/rpc/model/ApplicationModel.java#L80](https://github.com/apache/dubbo/blob/839d2a604e629ea9e96b964be09ae221e85312ba/dubbo-common/src/main/java/org/apache/dubbo/rpc/model/ApplicationModel.java#L80)

### Expected Result

```
initFrameworkExts
```
appConfigContent = dynamicConfiguration.getProperties
                        (isNotEmpty(configCenter.getAppConfigFile()) ? configCenter.getAppConfigFile() : configCenter.getConfigFile(),
                                appGroup
                        );
            }
            try {
                environment.setConfigCenterFirst(configCenter.isHighestPriority());
                environment.updateExternalConfigurationMap(parseProperties(configContent));
                environment.updateAppExternalConfigurationMap(parseProperties(appConfigContent));
            } catch (IOException e) {
                throw new IllegalStateException("Failed to parse configurations from Config Center.", e);
            }
            return dynamicConfiguration;
        }
        return null;
    }
    /**
     * Add an instance of {@link EventListener}
     *
     * @param listener {@link EventListener}
     * @return {@link DubboBootstrap}
     */
    public DubboBootstrap addEventListener(EventListener<?> listener) {
        eventDispatcher.addEventListener(listener);
        return this;
    }
    /**
     * export {@link MetadataService}
     */
    private void exportMetadataService() {