优化placeholder的显示

src/views/ppt_manage/newVersion/utils/tinymceSetting.js

@@ -56,9 +56,9 @@ export const setting = {
         editor.on('input',function(){
             let content = editor.getContent()
             if(content){
-                editor.getBody().classList.add('.placeholder-hidden')
+                editor.getBody().classList.add('placeholder-hidden')
             }else{
-                editor.getBody().classList.remove('.placeholder-hidden')
+                editor.getBody().classList.remove('placeholder-hidden')
             }
         })
     }