Support proxy domain validation for Garage web domains

Also rename the data bag item

site-cookbooks/sockethub/recipes/proxy.rb

@@ -24,10 +24,10 @@ file "/etc/letsencrypt/renewal-hooks/post/nginx" do
   group "root"
 end
 
-gandi_api_data_bag_item = data_bag_item('credentials', 'gandi_api_5apps')
+gandi_api_credentials = data_bag_item('credentials', 'gandi_api')
 
 template "/root/gandi_dns_certbot_hook.sh" do
-  variables gandi_api_key: gandi_api_data_bag_item["key"]
+  variables gandi_api_key: gandi_api_credentials["key"]
   mode 0770
 end