Update to be consistent with imported Jetty version

[jbentley1]

To review, compare against the Jetty implementation. This brings things current to the version of Jetty being imported.

https://h2oai.atlassian.net/browse/PUBDEV-8802

[michalkurka]

thank you @jbentley1 - I will take a look

[jbentleyEG]

Here is the changes that were originally made in that file, which I copied over into the updated version https://github.com/h2oai/h2o-3/commit/e92776121155bc40e46dc0dd0ac64a7676358402

[michalkurka]

Hi @jbentley1 - I don't think we can actually merge this PR as-is. The issue is that the default H2O assembly is built on Jetty 9 and the specific version is 9.4.11.v20180605. Your commit would upgrade the Response implementation to a different version which I don't think we can do without consequences.

I think the issue here is that we actually modify the class in the dependency. We should only be doing that in H2O assemblies - otherwise we can cause harm whenever someone includes H2O as a dependency but has a different Jetty version.

[michalkurka]

I will make a PR that corrects the dependencies

[michalkurka]

@jbentley1 please take a look at this PR and let me know what you think: https://github.com/h2oai/h2o-3/pull/6308