Revert "[Rails5] Explicitly set request.format for blob_controller"

This reverts commit 037334d2.

# Conflicts:
#	app/controllers/projects/blob_controller.rb

app/controllers/projects/blob_controller.rb

@@ -9,7 +9,6 @@ class Projects::BlobController < Projects::ApplicationController
   include ActionView::Helpers::SanitizeHelper
   prepend_before_action :authenticate_user!, only: [:edit]
 
-  before_action :set_request_format, only: [:edit, :show, :update, :destroy]
   before_action :require_non_empty_project, except: [:new, :create]
   before_action :authorize_download_code!
 
@@ -242,18 +241,6 @@ class Projects::BlobController < Projects::ApplicationController
       .last_for_path(@repository, @ref, @path).sha
   end
 
-  # In Rails 4.2 if params[:format] is empty, Rails set it to :html
-  # But since Rails 5.0 the framework now looks for an extension.
-  # E.g. for `blob/master/CHANGELOG.md` in Rails 4 the format would be `:html`, but in Rails 5 on it'd be `:md`
-  # This before_action explicitly sets the `:html` format for all requests unless `:format` is set by a client e.g. by JS for XHR requests.
-  def set_request_format
-    request.format = :html if set_request_format?
-  end
-
-  def set_request_format?
-    params[:id].present? && params[:format].blank? && request.format != "json"
-  end
-
   def show_html
     environment_params = @repository.branch_exists?(@ref) ? { ref: @ref } : { commit: @commit }
     @environment = EnvironmentsFinder.new(@project, current_user, environment_params).execute.last