Two small bugfixes

Hi Dustin,

great work! I was about to implement an SNI proxy myself when I found your project.
Testing on our server with clients not including the SNI extension I stumbled over these two minor bugs.

See Wireshark screen shot of the client hello request that could not be parsed by tls.c.

Best regards

Lars
![unbenannt](https://cloud.githubusercontent.com/assets/7404279/2799981/7e37f286-cc6a-11e3-93e7-32ddab266167.PNG)