Fix viewing default push rules on a Geo secondary

changelogs/unreleased-ee/4110-fix-push-rules-on-geo-secondary.yml

+---
+title: Fix viewing default push rules on a Geo secondary
+merge_request: 3559
+author:
+type: fixed

ee/app/controllers/admin/push_rules_controller.rb

@@ -40,6 +40,6 @@ class Admin::PushRulesController < Admin::ApplicationController
   end
 
   def push_rule
-    @push_rule ||= PushRule.find_or_create_by(is_sample: true)
+    @push_rule ||= PushRule.find_or_initialize_by(is_sample: true)
   end
 end

ee/app/views/admin/push_rules/show.html.haml

@@ -6,7 +6,7 @@
 
 %hr.clearfix
 
-= form_for [:admin, @push_rule] do |f|
+= form_for @push_rule, url: admin_push_rule_path, method: :put do |f|
   - if @push_rule.errors.any?
     .alert.alert-danger
       - @push_rule.errors.full_messages.each do |msg|