Version
1.4.10
Environment
"ant-design-vue": "1.4.9", "vue": "2.5.17"
Reproduction link

Steps to reproduce
自定义a-select-option的children后,下来列表的样式和选中不一样
What is expected?
自定义a-select-option的children后,下来列表的样式和选中一样
What is actually happening?
自定义a-select-option的children后,下来列表的样式和选中不一样