[Netfilter] Add missing rspamderror php...

data/web/_rspamderror.php

@@ -0,0 +1,12 @@
+<?php
+$redis = new Redis();
+try {
+  $redis->connect('redis-mailcow', 6379);
+}
+catch (Exception $e) {
+  exit;
+}
+header('Content-Type: application/json');
+echo '{"error":"Unauthorized"}';
+error_log("Rspamd UI: Invalid password by " . $_SERVER['REMOTE_ADDR']);
+$redis->publish("F2B_CHANNEL", "Rspamd UI: Invalid password by " . $_SERVER['REMOTE_ADDR']);