Fix behavior of sslmode=require with sslrootcert present
Fix behavior of sslmode=require with sslrootcert present

According to PostgreSQL documentation the behavior should be
the same as that of verify-ca sslmode

https://www.postgresql.org/docs/12/libpq-ssl.html

jackc/pgx,jackc/pgconn,jackc/pgconn,jackc/pgx,jackc/pgx,jackc/pgx