Adding args to PyLint in setting.json breaks linting #5257

Environment data

• VS Code version: 1.33.1
• Extension version : ms-python 2019.3.6558
• OS and version: Windows 10 Pro
• Python version (& distribution if applicable, e.g. Anaconda): 3.6.8
• Type of virtual environment used (N/A | venv | virtualenv | conda | ...): venv
• Relevant/affected Python packages and their versions:
  astroid 2.2.5
  colorama 0.4.1
  isort 4.3.17
  lazy-object-proxy 1.3.1
  mccabe 0.6.1
  pip 19.0.3
  pylint 2.3.1
  setuptools 40.6.2
  six 1.12.0
  typed-ast 1.3.1
  wrapt 1.11.1
  opencv-python 3.4.1.15

Adding any type of argument for PyLint to settings.json, seems to cause a major issue with linting.

For instance, adding this line to setting.json:

"python.linting.pylintArgs": ["--extension-pkg-whitelist=cv2"],

causes linting to bug out, outputting a bunch of warnings never seen before.

I have tested this with other commands as well, and all of them does the same thing.

Steps to reproduce:

1. Use linting on PyLint without any options in settings.py.
2. Add any setting using the "python.linting.pylintArgs" command
3. Rerun linting

Example errors

{
"resource": "/c:/Work/ucpa-machine-learning/src/find_gaps_v2.py",
"owner": "python",
"code": "mixed-indentation",
"severity": 4,
"message": "Found indentation with tabs instead of spaces",
"source": "pylint",
"startLineNumber": 13,
"startColumn": 1,
"endLineNumber": 13,
"endColumn": 1
}

{
"resource": "/c:/Work/ucpa-machine-learning/src/find_gaps_v2.py",
"owner": "python",
"code": "bad-whitespace",
"severity": 2,
"message": "No space allowed before comma",
"source": "pylint",
"startLineNumber": 29,
"startColumn": 39,
"endLineNumber": 29,
"endColumn": 39
}