Test "Set encode_keep_buffer(nil, true)" fails on Lua 5.5 #98

==> Test [118] Set encode_keep_buffer(nil, true) [throw error]: FAIL
[Input] { nil, true }
[Expected:error] { ONE_OF{ "bad argument #2 to '?' (found too many arguments)", "bad argument #2 to 'cjson.encode_keep_buffer' (found too many arguments)" } }
[Received:success] { true }

On Lua 5.5, unpacking { nil, true } doesn't yield nil, true like previous Lua versions, causing encode_keep_buffer() is called with no argument, thus succeeds unexpectedly.

This should be an expected behavior, per the specification for the table library,

Remember that, whenever an operation needs the length of a table, all caveats about the length operator apply (see §3.4.7).