REF: Remove etag check in 304 response.

The etag check in the 304 response function is redudant, since the
client already sends the etag to the server, and the check has already
been performed on the server side, which is precisely why we get back
a 304 response. This check is causing problem with some proxy servers,
and can safely be removed, IMO.
Merge pull request #78 from punchagan/remove-etag-check

REF: Remove etag check in 304 response.