Verify if registry is enabled in registry

app/controllers/projects/container_registry_controller.rb

 class Projects::ContainerRegistryController < Projects::ApplicationController
+  before_action :verify_registry_enabled
   before_action :authorize_read_container_image!
   before_action :authorize_update_container_image!, only: [:destroy]
   layout 'project'
@@ -19,6 +20,10 @@ class Projects::ContainerRegistryController < Projects::ApplicationController
   private
+  def verify_registry_enabled
+    render_404 unless Gitlab.config.registry.enabled
+  end
+
   def container_registry_repository
     @container_registry_repository ||= project.container_registry_repository
   end

app/helpers/projects_helper.rb

@@ -152,7 +152,7 @@ module ProjectsHelper
       nav_tabs << :builds
     end
-    if project.container_registry_repository_url.present? && can?(current_user, :read_container_image, project)
+    if Gitlab.config.registry.enabled && can?(current_user, :read_container_image, project)
       nav_tabs << :container_registry
     end