Website proof cancellation does not cancel

Steps to reproduce:

1. click "prove my website or domain"
2. enter domain, "prove this domain in the browser"
3. on the window containing "Please serve the below text at one of these URL's", instead of clicking "Ok, I posted! Check for it." click the x in the upper right. (Use case: user is just checking out what is required to prove their domain, but cannot upload a txt file at that time)
4. profile page still has "prove my website or domain" as the option.

Expected results: nothing happens.
Actual results: user receives email with subject "your web (example.com) proof has failed" a day or so later; is surprised that keybase.io was checking for it this whole time!

I've just gone through this process again to double check that it still happens (and that I got the steps to reproduce right), so I'll update this if I get another email.

Also, it appears that after a little while, going to the profile page will show a http (!) tag and a "This proof is pending" message, which seems wrong since the user never clicked "Okay, I posted! Check for it."

Reproduce the website or domain proof flow using the listed steps, especially closing the instruction window with the upper-right x. Trace the proof flow from the profile page and verify whether cancellation is recorded. Done means closing the window leaves no pending proof and sends no later failure email.