This should not be a big deal. The color space of the web is sRGB, gamma 2.2. Your HTTP client should only be seeing this ICC profile on the web unless, of course, a clueless poster is uploading photos with the wrong color space.
I'm guessing those instructions are for an older version. I also see only display_profile,mode, and rendering_intent, but my mode is set to 2 (I don't remember ever changing this before, but that doesn't mean much). I'm guessing the fact that my "mode" is set to 2 means it is enabled for me already. When I visit the site mentioned at the top of the thread, there are a couple sample images designed to test if your browser support ICC profiles, and as far as I can tell, Firefox 3.53 already does (the word "red" is already red, etc). Do other people see something different?
I just checked mine was already enabled but i don't like my colours perhaps it's because i'm blind