[fix] kodev wbuilder crashes with "attempt to index global 'G_defaults' (a nil value)" (#10088)

Fixes #10084.

tools/wbuilder.lua

@@ -1,11 +1,13 @@
 -- widget test utility
 -- usage: ./luajit tools/wtest.lua
 
-require "defaults"
 print(package.path)
 package.path = "common/?.lua;rocks/share/lua/5.1/?.lua;frontend/?.lua;" .. package.path
 package.cpath = "common/?.so;common/?.dll;/usr/lib/lua/?.so;rocks/lib/lua/5.1/?.so;" .. package.cpath
 
+-- Load default settings
+G_defaults = require("luadefaults"):open()
+
 local DataStorage = require("datastorage")
 local _ = require("gettext")