Implement [JENKINS-23665] Parameter to select alias ...

Hope this will be helpful also for others.
If you want to do me a favor, promote it into the next LTS as well.

If I may ask: 
Is there a reason that Jenkins ... sorry ... Winstone is locked to the 8.x branch of Jetty?

Daniel, thanks for the clarification. Of course your comments are welcome. So let me explain.

If you take a look at the PR, in the last paragraph it says:

> On the same subject, there is --httpsKeyStorePassword parameter but no 
> --httpsKeyPassword parameter. This will cause problems if the password of the private key 
> of the keystore is different from the password of the certificates private key, which is a 
> scenario that's even enforced to some extend in newer versions of the JVM keytool tool.)

Also the full title of the PR is "Parameter to select alias of SSL/TLS certificate for Jenkins Web UI, private key password"; note the last portion.

So one could argue that these are two changes in one PR and one pull request, though I'd argue they are closely related. We introduce *two* new command line parameters here and the code you refer to is required if the 2nd new parameter (--httpsKeyPassword) is set.

One could also take the stand that the whole portion of the code you are referring to could be deleted as the sole purpose of the whole code block is to generate some debug output in case the FULL_DEBUG log level is set.

I just wanted to be sure I don't break that part of the original code with my changes; which is what I would have done whenever --httpsKeyPassword would not be the same as --httpsKeyStorePassword.

HTH

Still waiting for a committer to look at this ...