tests/sitecustomize.py

tests: update py3 test since json fields are now sorted

The fields have been sorted since 814151cd8c4a (logcmdutil: rewrite
jsonchangeset printer to be backed by jsonformatter, 2018-04-13), and
the test case has thus been failing since that commit.

Differential Revision: https://phab.mercurial-scm.org/D3570

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