Remove unnecessary line configuring server's stderr. test_version_check.

pywebsocket server doesn't output anything annoying for this test case.

Release note: n/a

Review URL: https://codereview.appspot.com/8955043

git-svn-id: http://pywebsocket.googlecode.com/svn/trunk@766 4ff78f4a-9131-11de-b045-6380ec9940d4
[echo_client] Exit when an extension is enabled and an old protocol which does not support extensions is specified

Release note: Exit echo_client when an extension is enabled and an old protocol is specified.

Review URL: https://codereview.appspot.com/9072043

git-svn-id: http://pywebsocket.googlecode.com/svn/trunk@767 4ff78f4a-9131-11de-b045-6380ec9940d4