net/phpldapadmin: update to 1.2.6.6

ChangeLog: https://github.com/leenooks/phpLDAPadmin/compare/1.2.6.5...1.2.6.6

Another fix for CVE-2020-35132.

PR: 272348
Reported by: ports@bsdserwis.com (maintainer)
MFH: 2023Q3 (security fix)
Security: CVE-2020-35132