Update mixin.js
Update mixin.js

Typo fixed
datitisev/core,malayladu/core,Luceos/core,datitisev/core,malayladu/core,Luceos/core,malayladu/core,datitisev/core,flarum/core,Luceos/core,flarum/core,malayladu/core,Luceos/core,flarum/core,datitisev/core