You don't have any problem on your configuration.
Bitnami images come with SSL support already pre-configured and with a dummy certificate in place. Although this dummy certificate is fine for testing and development purposes, you will usually want to use a valid SSL certificate for production.
This dummy certificate is a self-signed certificate and that is the reason why your browser tells you that the connection is not secure when you access it through Https protocol. However, the connection is secure so you don't have to worry about it. You can add it as an exception on your browser.
If you want this message to disappear you need a valid SSL certificate for production and then configure your server properly, you can find information about how to do it at: