For ldapi:// connections, which connect - by definition - to a local UNIX
socket, lower the value of config setting 'ldap_ssl_verify_mode' to "NONE"
to avoid certificate validation failures.
The UNIX socket address can NEVER match any DNS name from a certificate,
making the whole certificate validation moot.
This is a workaround for a limitation of Python's LDAP modules, that do not
consider this edge case.
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