lua-nucleo/test/cases/0330-tpretty: fix compatibility with LuaJIT 2

[rafis]

The test 0330-tpretty seems oriented for Lua 5.1 only and has incompabilities with LuaJIT 2. This is due to differences in table traversal order in these interpreters.

[run]   test/cases/0330-tpretty.lua Suite `tpretty' failed:
 * Test `tpretty_ex-bug-concat-nil-full': lua-nucleo/ensure.lua:216: ensure_strequals: first result matches expected:
different at byte 114 (line 9, offset 1):

  expected   |ue_visits_total = "IN|
vs. actual   |ue_visits_yesterday =|


actual:
{
  result =
  {
    stats =
    {
      garden =
      {
        views_total = "INTEGER";
        unique_visits_yesterday = "INTEGER";
        id = "GARDEN_ID";
        views_yesterday = "INTEGER";
        unique_visits_total = "INTEGER";
      };
    };
  };
  events = { };
}
expected:
{
  result =
  {
    stats =
    {
      garden =
      {
        views_total = "INTEGER";
        unique_visits_total = "INTEGER";
        id = "GARDEN_ID";
        views_yesterday = "INTEGER";
        unique_visits_yesterday = "INTEGER";
      };
    };
  };
  events = { };
}

#2375