env_override_existing_values doesn't work if --envfile option is set

[Krops]

"override" is hardcoded by True. Suggest to add _override = early_config.getini("env_override_existing_values") to make this configurable

def pytest_sessionstart(session):
    config = session.config
    if config.getoption("envfile", default=None) is not None:
        load_dotenv(dotenv_path=config.getoption("envfile"), override=True)

[quiqua]

That is currently intentional as the description of this option points out:

pytest-dotenv/pytest_dotenv/plugin.py

Lines 17 to 21 in 866c90d

	parser.addoption("--envfile",
	dest="envfile",
	default="foo",
	type=str,
	help="Overwrite any environment variable specified in this file. This argument ignores the .ini settings.")

Feel free to open a PR and adjust the behaviour accordingly though.

[Krops]

@quiqua pls check https://github.com/quiqua/pytest-dotenv/pull/21/files