Removes memoization that doesn't seem to actually work and unnecessar…

…y if statement

09-intermediate-rails/controller-filters-contd.md

@@ -17,7 +17,7 @@ In the `app/controllers/application_controller.rb`:
   before_action :require_login
 
   def current_user
-    @current_user ||= User.find(session[:user_id]) if session[:user_id]
+    @current_user = User.find(session[:user_id])
   end
 
   def require_login