fix date-picker demo
fix date-picker demo

ant-design/ant-design-mobile,ant-design/ant-design-mobile,bccsafe/ant-design-mobile,bccsafe/ant-design-mobile,ant-design/ant-design-mobile,bccsafe/ant-design-mobile,ant-design/ant-design-mobile,bccsafe/ant-design-mobile,bccsafe/ant-design-mobile