[Minor] rbl check_types was missing images

diff --git a/lualib/plugins/rbl.lua b/lualib/plugins/rbl.lua
index af5d6bd91f4e40f97d7c96bd395513cc43dc7233..50cabd633fa8e1826801eabf2f937547bdd972bf 100644 (file)
--- a/lualib/plugins/rbl.lua
+++ b/lualib/plugins/rbl.lua
@@ -32,6 +32,7 @@ local check_types = {
   content_urls = {},
   numeric_urls = {},
   emails = {},
+  images = {},
   replyto = {},
   dkim = {},
   rdns = {