Revert back button behaviour
Revert back button behaviour

As of 25932cf, the back button was no longer shown if the user came in directly to a discussion. This caused problems on mobile where it was kind of hard to get back home without the button.

Albert221/core,Luceos/core,Luceos/core,flarum/core,flarum/core,renyuneyun/core,flarum/core,datitisev/core,Luceos/core,Albert221/core,renyuneyun/core,malayladu/core,malayladu/core,renyuneyun/core,malayladu/core,malayladu/core,Luceos/core,datitisev/core,renyuneyun/core,Albert221/core,Albert221/core,datitisev/core,datitisev/core