Commit 496980f breaks test 26.b

[FiachAntaw]

Running 'make test' after commit 496980f fails with a server-side handshake_failure in unit test 26.b.

This appears to be caused by filtering of the sha256 MACs in HandshakeSettings.validate() for pre-TLS 1.2 versions, which results in the server lacking any valid ciphersuites (hence no shared ciphersuites with client, hence handshake_failure). I suspect Fault.ignoreVersionForCipher is supposed to prevent this, but it only inhibits calls to CipherSuite.filterForVersion which was where filtering occurred previously.

I decided against submitting a pull request because I'm not sure what the preferred solution would be; three that come to mind are either to add fault injection to the HandshakeSettings object, to skip validation altogether if a fault has been injected, or to revert the filtering in validate() since it appears (at first glance) to be redundant.