Store layouts are not working with rails 6

[narch]

The "view" instance variable that is called at https://github.com/spree-contrib/spree-multi-domain/blob/d3e6c40962bbac13a2eb04069ed9f78e9edfeea4/lib/spree_multi_domain/engine.rb#L25 is no longer made available from the render method in ActionView::TemplateRenderer with Rails 6.