fix: prevent -m mode crash on single-label domains

[shbhmexe]

Summary

This PR fixes a crash when mapping unknown affiliations to email domains (-m) for emails whose domain has no dot (e.g. user@localhost). It also hardens date parsing in logparser.py to accept CommitDate: lines.

Background / Reasoning

• database.MapToEmployer() iterates domain suffixes to find domain mappings, but for single-label domains the suffix loop never runs, leaving addr undefined. When unknown == 1, this leads to an exception instead of producing a domain-based fallback.
• logparser.getDate() only skipped the Date: token; if the input contains CommitDate: (possible with git log --pretty=fuller), date parsing can fail.

Changes

• src/database.py
  • Ensure addr is always defined before domain suffix iteration.
  • Make GetHackerDomain() treat single-label domains as a real label (e.g. Localhost *) instead of producing " *".
• src/logparser.py
  • Ignore the CommitDate: token when extracting the date string.

Impact

• No behavior change for normal dot-separated domains (e.g. gmail.com, example.co.uk).
• Prevents a hard crash in -m mode for single-label domains.
• Improves robustness when CommitDate: lines are present in the git log input.

Compatibility / Non-overlap

• Based on current master (includes recent merges up through e5595aa1).
• Changes are isolated and do not revert or duplicate previously merged fixes.

Verification

• Change is intentionally minimal and guarded:
  • Existing behavior is unchanged for common inputs.
  • New behavior only applies to previously-crashing edge cases.
• No new features added.