handle stdout and stderr limits properly

[AbsoluteZero000]

the checking of the length of the stdout and stderr was checking on the stdout and stderr before the addition of the data characters so it passes any length of characters as long as passing the limit is in the same buffer.

basically

{
  "language": "python3",
  "version": "*",
  "files": [
    {
      "name": "test",
      "content": "print('h'*5000)"
    }
    
  ],
  "stdin": "2"
}

this passes when it shouldn't