It appears that when OpenSSL negotiates a 1.1 or 1.2 connection, and it
decides to renegotiate, the client will send a record with version "1.0"
rather than with the current TLS version.  This would cause the
connection to fail whenever both sides had OpenSSL 1.0.1, and the v2 Tor
handshake was in use.

As a workaround, disable TLS 1.1 and TLS 1.2.  When a later version of
OpenSSL is released, we can make this conditional on running a fixed
version of OpenSSL.

Alternatively, we could disable TLS 1.1 and TLS 1.2 only on the client
side.  But doing it this way for now means that we not only fix TLS with
patched clients; we also fix TLS when the server has this patch and the
client does not.  That could be important to keep the network running
well.

Fixes bug 6033.