ownCloud 9 MySQL not supported

I'm trying to install ownCloud 9 to FreeBSD 10 with nginx as web server. I am using this official manual, which tells me to use this command:

sudo -u www-data php occ  maintenance:install --database
"mysql" --database-name "owncloud"  --database-user "root" --database-pass
"password" --admin-user "admin" --admin-pass "password"

But I get this error:

[InvalidArgumentException]          
Database <mysql> is not supported.

This is very weird, because MySQL is listed as a supported database, and required modules are installed (wordpress is already working on this host with mysql database) and variables are set. If I start a web installation, I have only SQLite option available, like there are no any MySQL instance running on my host.

Some diagnostics:

# pkg info | grep mysql
mysql56-client-5.6.27          Multithreaded SQL database (client)
mysql56-server-5.6.27          Multithreaded SQL database (server)
php56-mysql-5.6.20             The mysql shared extension for php
php56-mysqli-5.6.20            The mysqli shared extension for php
# grep env /usr/local/etc/php-fpm.d/owncloud.conf
env[HOSTNAME] = $HOSTNAME
env[PATH] = /usr/local/bin:/usr/bin:/bin
env[TMP] = /tmp
env[TMPDIR] = /tmp
env[TEMP] = /tmp

I will appreciate any help.