Revert SSL version back to automatic detection

Summary:
See discussion in T2132. In D3767 I forced this to "3" to fix some problems users had reported here. However, users are now reporting problems with it being set to 3. After some more digging, I think the "3" camp is in the wrong, and possibly affected by an issue in libssl:

http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=666051
http://rt.openssl.org/Ticket/Display.html?id=2771&user=guest&pass=guest

In particular, the value of "1" for this field means TLSv1, which, unintuitively, is a newer protocol than a "3" value for this field to indicate SSLv3.

So, revert D3767 -- I'll push back on the v3 crowd. I can't reproduce any of this, but I have OpenSSL 0.9.8r 8 Feb 2011 and am not thrilled about spending all day building libssl versions until we get a more useful report.

Also improve the HTTP/S future test script slightly.

Test Plan: :(

Reviewers: vrana, btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T2132

Differential Revision: https://secure.phabricator.com/D4078