替换字体无法选择替换后的字体weight
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- [x] Make sure you are using the latest version of [WeSketch](https://github.com/weixin/WeSketch)
- [x] OS Version: `macOS (10.13.6)`
- [x] Sketch Version: `v50.0+`

#### Issues below

你好，在使用“替换字体”这个功能时，无法选择替换后的字体weight，比如pingfang字体的Medium或Bold无法进一步选择，默认会全部替换为regular，求大大解决，谢谢！