If you didn’t enable the .htaccess redirect in your site, you may see a new plus one, with a notice in your dashboard (since version 3.2)
WordPress 301 redirect enabled. We recommend to enable the .htaccess redirect option on your specific setup.
This setting is not enabled by default, because on some setups you may need to manually remove the .htaccess redirect if it causes issues. You should be able to edit your .htaccess manually, so you can remove the redirect if needed.
It is a recommended setting, because the .htaccess redirect is slightly faster, and the wp redirect might be less reliable in combination with caching.
You can enable the .htaccess redirect in settings/ssl/settings. Check the “.htaccess 301 redirect” option.
If you’re not comfortable with enabling this feature, you can dismiss the notice by clicking the “X”. No worries, the wp redirect works fine for the majority of the websites.