That is not a bug; the field is meant to make sure that you downloaded a build from the actual official website, not 3.5-367. I think it should be reworded so that people who don't read in full will understand it, but it basically says to check the box if you are using a build downloaded from this website (https://dolphin-emu.org/ instead of http://www. shall not be named). Thankfully, though, dolphin-emulator doesn't seem to be the top result on google anymore, so it's slightly less important than when it WAS the top result.
in a perfect world we would all be piles of sand with no ability to form coherent bodies of body