tests/sitecustomize.py

test-check-py3-compat: remove false output from "python3 check-py3-compat.py"

If python3 were python2, these errors would be reported, but we're running
check-py3-compat.py on Python 3 here.

from __future__ import absolute_import
import os

if os.environ.get('COVERAGE_PROCESS_START'):
    try:
        import coverage
        import uuid

        covpath = os.path.join(os.environ['COVERAGE_DIR'],
                               'cov.%s' % uuid.uuid1())
        cov = coverage.coverage(data_file=covpath, auto_data=True)
        cov._warn_no_data = False
        cov._warn_unimported_source = False
        cov.start()
    except ImportError:
        pass