Update jetty-alpn-agent for latest java8 release.
Update jetty-alpn-agent for latest java8 release.

Motivation:

We need to update jetty-alpn-agent to support java 1.8.0_162 while running our tests / examples.

Modifications:

Update jetty-alpn-agent to 2.0.7

Result:

All tests alpn related tests work again on latest java8 version

kiril-me/netty,kiril-me/netty,kiril-me/netty,kiril-me/netty,kiril-me/netty