Security update for postgresql96 (important)

This update for postgresql96 fixes the following issues:

• CVE-2017-7547: Further restrict visibility of
  pg_user_mappings.umoptions, to protect passwords stored as user mapping
  options. (bsc#1051685)
• CVE-2017-7546: Disallow empty passwords in all password-based
  authentication methods. (bsc#1051684)
• CVE-2017-7548: lo_put() function ignores ACLs. (bsc#1053259)

The changelog for this release is here:
<a href=“https://www.postgresql.org/docs/9.6/static/release-9-6-4.html”>https://www.postgresql.org/docs/9.6/static/release-9-6-4.html</a>