- Don't call the keylog function if it has already logged the key.
For old OpenSSL versions and its forks that do not have support for
OpenSSL's keylog callback, libcurl has its own legacy key logging
function that logs the TLS 1.2 (and earlier) key (client random + master
key) on a single line.
Prior to this change, since e7de80e8 (precedes 8.8.0), the legacy key
logging function could write the same key line more than once (usually
twice) due to some incorrect logic.
Closes https://github.com/curl/curl/pull/13683
02b14378e6