Import Postfix 2.9.7. Changes since version 2.9.5:
- Thanks to OpenSSL documentation, the Postfix 2.9.0..2.9.5 SMTP
  client and server used an incorrect procedure to compute TLS
  certificate PUBLIC-KEY fingerprints (these may be used in the
  check_ccert_access and in smtp_tls_policy_maps features). Support
  for certificate PUBLIC-KEY finger prints was introduced with Postfix
  2.9; there is no known problem with the certificate fingerprint
  algorithms available since Postfix 2.2.
  Specify "tls_legacy_public_key_fingerprints = yes" temporarily,
  pending a migration from configuration files with incorrect Postfix
  2.9.0..2.9.5 certificate PUBLIC-KEY finger prints, to the correct
  fingerprints used by Postfix 2.9.6 and later.
- Bugfix (introduced: Postfix 2.0): when myhostname is not listed in
  mydestination, the trivial-rewrite resolver may log "do not list in both
  mydestination and ". The fix is to re-resolve a domain-less address after
  adding $myhostname as the surrogate domain, so that it pops out with the
  right address-class label. Reported by Quanah Gibson-Mount.
- Bugfix (introduced: Postfix 2.3): don't reuse TCP connections when
  smtp_tls_policy_maps is specified. TLS policies may depend on the remote
  destination, but the Postfix <2.11 SMTP connection cache client does not
  distinguish between different destinations that resolve to the same
  IP address. Victor Duchovni. Found during Postfix 2.11 code maintenance.
- Bugfix (introduced: Postfix 2.2): don't reuse TCP connections when
  SASL authentication is enabled. SASL passwords may depend on the
  remote SMTP server hostname, but the Postfix <2.11 SMTP connection
  cache client does not distinguish between different hostnames that
  resolve to the same IP address. Found during Postfix 2.11 code
  maintenance.