Better compatibility with SSH clients (eg, Jenkins/BlueOcean) and add EdDSA key support by upgrading sshd
Hello! Two commits here. First one is the minimum needed to make Gitblit work with Jenkins/BlueOcean (resolves the "MAC corrupt" exception). It upgrades sshd to 1.2.0 with no further changes. Second one upgrades sshd to 1.6.0, and adds a dependency on eddsa, and adds code to register this provider, which in fact (tested) adds support for my new ED25519 ssh key. It also upgrades JGit to a newer point release which is supposed to fix bugs only. I'm running two production instances of Gitblit with these patches, and finally enjoying Gitblit + Jenkins/Blueocean pipelines.
There's a Jenkins issue that would be resolved with this. JENKINS-45769 -- I did not dare try to fix this on Jenkins side.
Some proof of EdDSA support...
On the web interface:

Via SSH "keys which"...

Though I do not use ED25519, I have merged your commits to our Gitblit server and it works. I have been missing this merge work for a long time. You made my day. Good work. Thank you.
I'm reopening this pull request since only one commit was merged and the support for eddsa is still pending.