gluon-setup-mode: remove obsolete migration

package/gluon-setup-mode/luasrc/lib/gluon/upgrade/310-setup-mode-migrate

-#!/usr/bin/lua
-
-local uci = require('simple-uci').cursor()
-
-
-local old = uci:get_first('gluon-config-mode', 'wizard', 'configured')
-if old == '1' then
-	local setup_mode = uci:get_first('gluon-setup-mode', 'setup_mode')
-	uci:set('gluon-setup-mode', setup_mode, 'configured', true)
-
-	uci:save('gluon-setup-mode')
-end
-
-os.remove('/etc/config/gluon-config-mode')