:bug: audio format `mp4` -> `mp3`

src/routes/Resource/AudioBook/AudioBookCreate.js

@@ -165,7 +165,7 @@ export default class AudioBookCreatePage extends PureComponent {
             <Form.Item label="音频格式" {...formItemLayout}>
               {getFieldDecorator('audioFormat', {
                 rules: [{ required: true, message: '音频格式不能为空!' }],
-                initialValue: (audio || {}).format || 'mp4',
+                initialValue: (audio || {}).format || 'mp3',
               })(
                 <Input disabled />
               )}