Update doc link on IP restriction

ee/app/views/groups/settings/_ip_restriction.html.haml

@@ -13,5 +13,5 @@
     - else
       = ip_restriction_form.text_field :range, class: 'form-control', placeholder: _('Enter IP address range')
     .form-text.text-muted
-      - read_more_link = link_to(_('Read more'), 'https://gitlab.com/gitlab-org/gitlab-ee/issues/1985')
+      - read_more_link = link_to(_('Read more'), help_page_path('user/group/index', anchor: 'ip-access-restriction-ultimate'))
       = _('This group, including all subgroups, projects and git repositories, will only be reachable from the specified IP address range. Example: <code>192.168.0.0/24</code>. %{read_more_link}.').html_safe % { read_more_link: read_more_link }