Remove some old documentation about a deleted test system in json.lua [ci skip]

nselib/json.lua

@@ -2,10 +2,6 @@
 -- Library methods for handling JSON data. It handles JSON encoding and
 -- decoding according to RFC 4627.
 --
--- There is a test section at the bottom which shows some example
--- parsing. If you want to parse JSON, you can test it by pasting sample JSON
--- into the <code>TESTS</code> table and run the <code>test</code> method
---
 -- There is a straightforward mapping between JSON and Lua data types. One
 -- exception is JSON <code>NULL</code>, which is not the same as Lua
 -- <code>nil</code>. (A better match for Lua <code>nil</code> is JavaScript