Hi @dantearaujo!
Welcome to the community! 
The HTTP Request node is reading the site’s content type as it is displayed. And the site’s encoding is in iso-8859-1, which is a bit old school. n8n uses UTF-8.
In order to convert the content type you’d need to install a library like iconv-lite and then add a Code Node to your workflow to convert the source code into UTF-8.
This will only work on a self-hosted environment, so good thing you’re already hosting 
If you want to go down that route, you can follow this article to help you set up the library.
This community post also has some useful info on importing a library to use in the Code Node
Hope this helps!
Happy Building! 