fix ApplicationController path on Action View guides
fix ApplicationController path on Action View guides

Since Rails 2.3, the ApplicationController path is
app/controllers/application_controller.rb, as stated on
its release notes:
https://guides.rubyonrails.org/2_3_release_notes.html#application-controller-renamed

MSP-Greg/rails,yahonda/rails,MSP-Greg/rails,yawboakye/rails,rails/rails,rails/rails,kmcphillips/rails,MSP-Greg/rails,Erol/rails,kmcphillips/rails,BlakeWilliams/rails,Edouard-chin/rails,esparta/rails,kddeisz/rails,Edouard-chin/rails,rails/rails,yawboakye/rails,yahonda/rails,Erol/rails,BlakeWilliams/rails,kddeisz/rails,esparta/rails,esparta/rails,rails/rails,BlakeWilliams/rails,georgeclaghorn/rails,esparta/rails,BlakeWilliams/rails,yahonda/rails,georgeclaghorn/rails,kddeisz/rails,yawboakye/rails,kmcphillips/rails,georgeclaghorn/rails,Edouard-chin/rails,yawboakye/rails,Erol/rails,MSP-Greg/rails,kmcphillips/rails,Erol/rails,kddeisz/rails,georgeclaghorn/rails,Edouard-chin/rails,yahonda/rails