RFR: 8352706: httpclient HeadTest does not run on HTTP2

[Michael McMahon]

On Mon, 24 Mar 2025 11:34:23 GMT, Daniel Jeliński <djelinski at openjdk.org> wrote:

> The test was using incorrect URIs for testing, and as a result, the test was never run on HTTP2. Additionally, the HTTP2 test server was using an unconfigured SSLContext, and HTTPS was not usable. Both issues are fixed.
> 
> The test continues to pass.

LGTM

-------------

Marked as reviewed by michaelm (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/24191#pullrequestreview-2710948046