PostgreSQL-Driver doesn't support user defined ports

There is no definition of a port in the dsn string (used for pg_connect): https://github.com/joomla/joomla-cms/blob/staging/libraries/joomla/database/driver/postgresql.php#L119

I have compared it with ownCloud (where I know it works): https://github.com/owncloud/core/blob/master/lib/private/setup/postgresql.php#L21

I have (not well enough) tested the "// Fix database with port connection"-fix from ownCloud and it works with the default "localhost:1234" syntax. (But I don't know what happen if "port=false".)

      // Fix database with port connection
      $e_host = $this->options['host'];
      if(strpos($e_host, ':')) {
         list($e_host, $port)=explode(':', $e_host, 2);
      } else {
         $port=false;
      }

      // Build the DSN for the connection.
      $dsn = "host='$e_host' port='$port' dbname={$this->options['database']} user={$this->options['user']} password={$this->options['password']}";

Maybe someone finds a better solution.