Check whether the bootstrap time triggers neterrors

Reported from @dcf on #tor-anticensorship:

dcf1 | I suspect there may be a bug in Tor Browser where it counts the time taken to bootstrap towards the time to connect to the first URL you enter, or something like that.

dcf1 | I've noticed it when using Snowflake. It seems that, frequently, the very first site I try to access, it says "the connection has timed out". But I click the "Try Again" button and it works.

dcf1 | My hunch is that it's because Snowflake takes longer to bootstrap, and Firefox's timeout timer is running during that time. That's just a guess.

dcf1 | The "The connection has timed out" for the first access comes back quicker than it should, it seems to me.