value-format="yyyy-MM-dd" 和default-value 不能同时存在，否则default-value不生效

### Description

Explain the issue you met, and describe what you expected to be. If you can write in English, we will be very grateful.

### Reproduce Steps

1. [First Step]

默认日期不生效
2. [Second Step]
去掉value-format="yyyy-MM-dd" 默认日期生效
3. [and so on...]
如果这个插件是在一个for循环里面的话，如果两者同时存在，第一个生效，其他不生效
### Error Trace (if possible)

It's better to post up the error stack for us to trace this issue.

### Solution

What needs to be done to address this issue? Ideally, provide a pull request with a fix.

### Additional Information

Any additional information, configuration or data that might be necessary to reproduce the issue.