Disable PostgreSQL SSL compression by default

Note that you can have SSL enabled but compression disabled. We found that in production, replicas using SSL compression added significant jitter in the replication delay and increased CPU utilization on both the client and the server. Disabling SSL compression is done by default on most Web servers (e.g. NGINX, Apache) and client libraries (e.g. curl) for security reasons (e.g. to mitigate the CRIME exploit).