Fix the typo in header name Sec-WebSocket-Key1 and Sec-WebSocket-Key2.
Fix the typo in header name Sec-WebSocket-Key1 and Sec-WebSocket-Key2.

The second S must be capitalized. This typo doesn't have any effect on the
behavior of handshake processor, but gives wrong description string for
exception thrown in _get_key_value.
Review URL: http://codereview.appspot.com/4437058

git-svn-id: d23f85197b9dafcb1b1682eb9d0eda70517bdc52@454 4ff78f4a-9131-11de-b045-6380ec9940d4

bpsinc-native/src_third_party_pywebsocket_src,bpsinc-native/src_third_party_pywebsocket_src,bpsinc-native/src_third_party_pywebsocket_src,bpsinc-native/src_third_party_pywebsocket_src