Extended from Osixia/phpldapadmin

• Adds ca-certificates package
• Points ldap.conf TLS_CACERT to a pem file under /etc/ssl/certs specified by
• Rips out the config.php bootstrap from startup
• Rips out most of the ldap client startup, opting to use a system CA cert instead
• Expects an existing config (ie a volume mounted configMap) present at /container/service/phpldapadmin/assets/config/config.php
• The read-only config mount will be copied to /var/www/phpldapadmin/config/config.php at startup and chowned to www-data