[Rework] Antivirus: Move antivirus routines to lua_scanners

lualib/lua_scanners/init.lua

+--[[
+Copyright (c) 2018, Vsevolod Stakhov <vsevolod@highsecure.ru>
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+]]--
+
+--[[[
+-- @module lua_scanners
+-- This module contains external scanners functions
+--]]
+
+local exports = {
+  antivirus = require "antivirus",
+}
+
+return exports

src/plugins/lua/antivirus.lua

 local rspamd_regexp = require "rspamd_regexp"
 local lua_util = require "lua_util"
 local fun = require "fun"
-local lua_antivirus = require "lua_antivirus"
+local lua_antivirus = require("lua_scanners").antivirus
 local redis_params
 
 local N = "antivirus"