Fix visibility settings UI in admin area

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

app/views/admin/application_settings/_form.html.haml

@@ -42,11 +42,11 @@
       = f.label :default_branch_protection, class: 'control-label col-sm-2'
       .col-sm-10
         = f.select :default_branch_protection, options_for_select(Gitlab::Access.protection_options, @application_setting.default_branch_protection), {}, class: 'form-control'
-    .form-group
+    .form-group.project-visibility-level-holder
       = f.label :default_project_visibility, class: 'control-label col-sm-2'
       .col-sm-10
         = render('shared/visibility_radios', model_method: :default_project_visibility, form: f, selected_level: @application_setting.default_project_visibility, form_model: 'Project')
-    .form-group
+    .form-group.project-visibility-level-holder
       = f.label :default_snippet_visibility, class: 'control-label col-sm-2'
       .col-sm-10
         = render('shared/visibility_radios', model_method: :default_snippet_visibility, form: f, selected_level: @application_setting.default_snippet_visibility, form_model: 'Snippet')