Move the `version_check_enabled` check from view to helper

app/helpers/version_check_helper.rb

 module VersionCheckHelper
   def version_status_badge
-    if Rails.env.production?
+    if Rails.env.production? && current_application_settings.version_check_enabled
       image_tag VersionCheck.new.url
     end
   end

app/views/help/index.html.haml

@@ -5,7 +5,6 @@
     - if current_user && current_user.admin?
       %span= Gitlab::VERSION
       %small= Gitlab::REVISION
-      - if current_application_settings.version_check_enabled
       = version_status_badge
   %p.slead
     GitLab is open source software to collaborate on code.

spec/views/help/index.html.haml_spec.rb

@@ -49,7 +49,6 @@ describe 'help/index' do
 
   def stub_helpers
     allow(view).to receive(:markdown).and_return('')
-    allow(view).to receive(:current_application_settings).
-      and_return(double.as_null_object)
+    allow(view).to receive(:version_status_badge).and_return('')
   end
 end