Update doc

package_README.html

@@ -63,7 +63,7 @@ directory. Check out deflatehd and inflatehd commands.</p>
 <p>We started to implement HTTP-draft-07/2.0
 (<a class="reference external" href="http://tools.ietf.org/html/draft-ietf-httpbis-http2-07">http://tools.ietf.org/html/draft-ietf-httpbis-http2-07</a>) and the
 header compression
-(<a class="reference external" href="http://tools.ietf.org/html/draft-ietf-httpbis-header-compression-07">http://tools.ietf.org/html/draft-ietf-httpbis-header-compression-07</a>).</p>
+(<a class="reference external" href="http://tools.ietf.org/html/draft-ietf-httpbis-header-compression-04">http://tools.ietf.org/html/draft-ietf-httpbis-header-compression-04</a>).</p>
 <p>The nghttp2 code base was forked from spdylay project.</p>
 <table border="1" class="docutils">
 <colgroup>