[Test] Remove test case with non-deterministic result

Removed test case does not work with luajit-2.1 anymore as it depends on
internal behavior of lujait-2.0.

The order of URL list returned by `extract_specific_urls` function from
`lualib/lua_util` depends on order of keys in table of TLDs.  The test
case incorrectly expects "net" and "com" being in front of the table,
however, "org" can appear there as well.

test/lua/unit/lua_util.extract_specific_urls.lua

@@ -108,7 +108,6 @@ context("Lua util - extract_specific_urls plain", function()
   local cases = {
     {expect = url_list, filter = nil, limit = 9999, need_emails = true, prefix = 'p'},
     {expect = {}, filter = (function() return false end), limit = 9999, need_emails = true, prefix = 'p'},
-    {expect = {"domain4.co.net", "test.com"}, filter = nil, limit = 2, need_emails = true, prefix = 'p'},
     {expect = {"domain4.co.net", "test.com", "domain3.org"}, filter = nil, limit = 3, need_emails = true, prefix = 'p'},
     {
       expect = {"gov.co.net", "tesco.co.net", "domain1.co.net", "domain2.co.net", "domain3.co.net", "domain4.co.net"},