Invalid config is warned twice and blocks package.json fallback

[Taiki92777]

Summary

Invalid react-doctor.config.json handling has two problems:

1. parse warning is logged twice in a single run
2. fallback to package.json reactDoctor config is skipped

Current behavior

When react-doctor.config.json is malformed, loadConfig logs a warning and returns early. This causes:

• duplicated warning output (config loaded in two places)
• no fallback to embedded package.json config

Reproduction

1. Put malformed JSON in react-doctor.config.json.
2. Add valid reactDoctor config in package.json.
3. Run react-doctor ..

Observed:

• parse warning appears twice
• behavior does not use valid fallback config from package.json

Expected behavior

• parse warning should appear once per run
• malformed react-doctor.config.json should still allow fallback to package.json reactDoctor

[Taiki92777]

Proposed fix is in PR #54: #54

[aidenybai]

Fixed in #68: loadConfig now falls through to package.json reactDoctor config when the config file fails to parse.