Logging in for the very first time always fails (in production), works on 2nd try

[carols10cents]

What happened:

• I cleared all cookies out of Chrome
• I visited crates.io
• I logged in
• Instead of loading /me, I got the error "Failed to log in: must be logged in to perform that action"
• If I reload the page and log in again, it works

On preliminary investigation, it looks like the TrustedUserId extension isn't being set in time before being read, but you get like half logged in and the cookie gets set so that the next time you log in, the extension is set. Investigating further now.