Fix extended master secret implementation in tlslite

Fix extended master secret implementation in tlslite

The previous cl (http://crrev.com/1306553002) didn't properly handle the field
in HandshakeSettings, resulting in extended master secret always being enabled,
regardless of what was passed in.

BUG=467312
Committed: https://crrev.com/b6248b5a92ab416011b4aadcb40adc83cab00c35
Cr-Commit-Position: refs/heads/master@{#344846}

[nharper, 2015-08-21 20:01:30]

nharper@chromium.org changed reviewers:
+ davidben@chromium.org

[davidben, 2015-08-21 20:02:30]

Bah, I should have noticed that. That's bitten me so many times... lgtm.

[nharper, 2015-08-21 20:03:54]

The CQ bit was checked by nharper@chromium.org

[commit-bot: I haz the power, 2015-08-21 20:05:11]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1301403002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1301403002/1

[commit-bot: I haz the power, 2015-08-21 20:18:48]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-08-21 20:19:24]

Patchset 1 (id:??) landed as
https://crrev.com/b6248b5a92ab416011b4aadcb40adc83cab00c35
Cr-Commit-Position: refs/heads/master@{#344846}