[Fix] Use tld when looking for DKIM domains

Issue: #2646

src/plugins/lua/reputation.lua

@@ -108,7 +108,8 @@ local function gen_dkim_queries(task, rule)
       local dom,res = lpeg.match(gr, opt)
 
       if dom and res then
-        ret[dom] = res
+        local tld = rspamd_util.get_tld(dom)
+        ret[tld] = res
       end
     end
   end

src/plugins/lua/whitelist.lua

@@ -162,9 +162,11 @@ local function whitelist_cb(symbol, rule, task)
       if dkim_opts then
         fun.each(function(val)
             if val[2] == '+' then
-              find_domain(val[1], 'dkim_success')
+              local tld = rspamd_util.get_tld(val[1])
+              find_domain(tld, 'dkim_success')
             elseif val[2] == '-' then
-              find_domain(val[1], 'dkim_fail')
+              local tld = rspamd_util.get_tld(val[1])
+              find_domain(tld, 'dkim_fail')
             end
           end,
             fun.map(function(s)