Remove adhoc natsconf config generation

[wallyqs]

In latest release of the server v1.1.0, JSON would be supported for configuring the server: nats-io/nats-server#653
This would mean that can remove the current config generation and just convert to JSON:

nats-operator/pkg/conf/natsconf.go

Lines 52 to 73 in bb45bba

	func Marshal(conf *ServerConfig) ([]byte, error) {
	js, err := json.MarshalIndent(conf, "", " ")
	if err != nil {
	return nil, err
	}
	if len(js) < 1 || len(js)-1 <= 1 {
	return nil, ErrInvalidConfig
	}
	// Slice the initial and final brackets from the
	// resulting JSON configuration so gnatsd config parsers
	// almost treats it as valid config.
	js = js[1:]
	js = js[:len(js)-1]
	// Replacing all commas with line breaks still keeps
	// arrays valid and makes the top level configuration
	// be able to be parsed as gnatsd config.
	result := bytes.Replace(js, []byte(","), []byte("\n"), -1)
	return result, nil
	}