Avoid logging about missing cert keys if not adding a trust cert.
Review Request #15018 — Created April 16, 2026 and updated — Latest diff uploaded
When building an SSL context, we were logging when a key for a trust
cert couldn't be found when there wasn't even a trust cert to begin
with. We now log this only when we know we have a cert but no key.
Hit this while testing another change and verified it was fixed.