Fix duplicate CI variable feature spec failure

spec/support/features/variable_list_shared_examples.rb

@@ -263,7 +263,7 @@ shared_examples 'variable list' do
 
     # We check the first row because it re-sorts to alphabetical order on refresh
     page.within('.js-ci-variable-list-section') do
-      expect(find('.js-ci-variable-error-box')).to have_content('Variables key has already been taken')
+      expect(find('.js-ci-variable-error-box')).to have_content('Validation failed Variables Duplicate variables: samekey')
     end
   end
 end