Move local broadcast domain preference to the interface settings and show warnings

A dismissable warning is shown if DHCP traffic has been seen on the currrent interface.

scripts/lua/update_prefs.lua

@@ -0,0 +1,26 @@
+--
+-- (C) 2013-18 - ntop.org
+--
+
+local dirs = ntop.getDirs()
+package.path = dirs.installdir .. "/scripts/lua/modules/?.lua;" .. package.path
+
+require "lua_utils"
+local json = require "dkjson"
+
+local res = {success = false}
+local ifid = _POST["ifid"]
+
+sendHTTPHeader('application/json')
+
+if isAdministrator() then
+  if _POST["action"] == "move-rrd-to-influxdb" then
+    ntop.setPref("ntopng.prefs.disable_ts_migration_message", "1")
+    res.success = true
+  elseif _POST["action"] == "host-id-message-warning" then
+    ntop.setPref(string.format("ntopng.prefs.ifid_%u.disable_host_identifier_message", ifid), "1")
+    res.success = true
+  end
+end
+
+print(json.encode(res))