Hi everyone,
I installed Openproject on my server with CentOS 6 with MySQL 5.1.73 and it works like a charm. Great project!
But unfortunately I have to upgrade to CentOS 7. With default installation - yum install openproject-ce MariaDB was installed and after I ran openproject-ce configure , it failed with:

Application.initialize!… rake aborted!
Incorrect MySQL client library version! This gem was compiled for 5.1.73 but the client library is 5.5.40-MariaDB.

Can I recompile gem in delivered ruby? (Ruby is in /opt/openproject-ce/vendor/bundle/ruby/2.1.0/gems directory)
And my second question - how can I change Selected addons? We have many PostgreSQL servers, so I will be very happy, if I can switch from MySQL to PostgreSQL.

Thanks

Marek