[Minor] Reduce hfilter log noise

src/plugins/lua/hfilter.lua

@@ -188,6 +188,7 @@ local config = {
 local compiled_regexp = {} -- cache of regexps
 local check_local = false
 local check_authed = false
+local N = "hfilter"
 
 local function check_regexp(str, regexp_text)
   local re = compiled_regexp[regexp_text]
@@ -228,7 +229,7 @@ local function check_host(task, host, symbol_suffix, eq_ip, eq_host)
   local function check_host_cb_mx(_, to_resolve, results, err)
     task:inc_dns_req()
     if err and (err ~= 'requested record is not found' and err ~= 'no records with this name') then
-        rspamd_logger.infox(task, 'error looking up %s: %s', to_resolve, err)
+        rspamd_logger.debugm(N, task, 'error looking up %s: %s', to_resolve, err)
     end
     if not results then
       task:insert_result('HFILTER_' .. symbol_suffix .. '_NORES_A_OR_MX', 1.0,