Fix error when rendering deleted user
Fix error when rendering deleted user

amdad/mentions,flarum/flarum-ext-mentions,sijad/flarum-ext-mentions,flarum/flarum-ext-mentions,flarum/flarum-ext-mentions,sijad/flarum-ext-mentions,flarum/mentions,amdad/mentions,flarum/mentions,sijad/flarum-ext-mentions