fix: raise RoutingError to return 404 page

Author: mroderick

app/controllers/invitations_controller.rb

@@ -88,7 +88,7 @@ def cancel_meeting
 
   def set_invitation
     @invitation = Invitation.find_by(token: params[:token])
-    head :not_found unless @invitation
+    raise ActionController::RoutingError, 'Invitation not found' unless @invitation
   end
 
   def load_invitation