When a client sends no SNI is a common situation. But currently the server
processes it as an error and returns SSL_TLSEXT_ERR_ALERT_FATAL causing
termination of a current TLS session. The problem occurs if configuration has
more than one certificate bundle in a listener.
This fix changes the return code to SSL_TLSEXT_ERR_OK and the log level of a
message.
f965e358b6