Merge branch '3498-error-500-due-to-promote-group-web-hooks' into 'master'

Resolve "Error 500 due to promote group Web hooks"

Closes #3498

See merge request gitlab-org/gitlab-ee!2972

app/helpers/license_helper.rb

@@ -75,8 +75,9 @@ def new_trial_url
   end
   def upgrade_plan_url
-    if  @project.group
-      group_billings_path(@project.group)
+    group = @project&.group || @group
+    if group
+      group_billings_path(group)
     else
       profile_billings_path
     end

ee/app/views/shared/promotions/_promotion_link_project.html.haml

 - short_form = local_assigns.fetch :short_form, false
 - if current_application_settings.should_check_namespace_plan?
-  - if can?(current_user, :admin_namespace, @project.namespace)
+  - namespace = @project&.namespace || @group
+  - if can?(current_user, :admin_namespace, namespace)
     = link_to 'Upgrade your plan', upgrade_plan_url, class: 'btn btn-primary'
-  - elsif @project.group
-    %p Contact an owner of group #{ @project.group.name } to upgrade the plan.
+  - elsif namespace.is_a?(Group)
+    %p Contact an owner of group #{ namespace.name } to upgrade the plan.
   - else
-    - owner = @project.namespace.owner
+    - owner = namespace.owner
     %p Contact owner #{ link_to(owner.name, user_path(owner)) } to upgrade the plan.
 - elsif current_user&.admin?
   - if License.current&.expired?