需要加强一下判断，避免editor.braftFinder为null时导致报错

[超能刚哥]

braft-editor/src/configs/handlers.js

Line 185 in b9f4c61

 file && file.type.indexOf('image') > -1 && editor.braftFinder.uploadImage(file, image => { 

[husky]

嘛时候这个 editor.braftFinder 会为null