THRIFT-2831 - Removes dead code in web_server.js introduced in THRIFT-2819

The commit https://issues.apache.org/jira/browse/THRIFT-2819 introduced dead code in web_server.js.

Sorry it was introduced by me.
The web_server.js was working totally fine even in binary cases.
My code actually does nothing.

This pull request will remove my changes.
What was I thinking.. ;)

Of course all tests still pass.