Lower the log level of failed connections

[ayazhafiz]

These are filled with messages like "received corrupted message of type
Handshake", which signify failures in the TLS connection, likely from
aborted or immaterial requests. They cover up more material errors, so
lower their level.

[github-actions]

✅ Bigtest for 09bedf0 (run)

Benchmarks:

• RSpec: 14.63% overhead
  • RSpec time: 17.77 seconds
  • ABQ time: 20.37 seconds
• RSpec parallel, 10 runs: max 13.11% overhead
  • min 7.65% overhead
  • standard deviation: 2.04%
• Jest: 7.23% overhead
  • Jest time: 20.634 seconds
  • ABQ time: 22.126 seconds

Fuzz result sizes:

• PASSED