Error 500 due to promote group Web hooks

https://sentry.gitlap.com/gitlab/gitlabcom/issues/47504/

NoMethodError: undefined method `namespace' for nil:NilClass
  app/views/groups/hooks/index.html.haml:27:in `_app_views_groups_hooks_index_html_haml___3697099546527846429_70188999586860'
    = render 'shared/promotions/promote_group_webhooks'
  lib/gitlab/i18n.rb:46:in `with_locale'
    yield
  lib/gitlab/i18n.rb:52:in `with_user_locale'
    with_locale(user&.preferred_language, &block)
  app/controllers/application_controller.rb:334:in `set_locale'
    Gitlab::I18n.with_user_locale(current_user, &block)
  lib/gitlab/middleware/multipart.rb:93:in `call'
    return @app.call(env) if encoded_message.blank?
...
(188 additional frame(s) were not displayed)

ActionView::Template::Error: undefined method `namespace' for nil:NilClass

ActionView::Template::Error: undefined method `namespace' for nil:NilClass