Ensure logging configuration is loaded in plugin manager

[spinscale]

This prevents log4j warnings printed out, when installing a plugin
due to the JarHell class using an ESLogger.

Closes #12064

[dadoonet]

LGTM

[dadoonet]

I think we also have this issue when running REST tests in plugins BTW. Or when running tests from IntelliJ in plugins.

[spinscale]

@dadoonet can you show me how to reproduce that? RestTests are running fine for me, with logging...also in intellij

[rmuir]

Looks good. I think @dadoonet refers to the new rest tests mechanism that runs in mvn verify. You can run it with mvn verify -Dskip.unit.tests to see. This mechanism unzips the elasticsearch.zip and installs the plugin with bin/plugin, before running rest tests against that external cluster, so thats why you see it there.

[rmuir]

and also thanks for tracking this one down :)

[spinscale]

ah, so in order to not have the messages occur in mvn verify, I had to run mvn install before - which is obvious after reading the ant file. If we want to have run this as part of the release, we just shouldnt forget to run that, as we dont do know. will get it in, in a sec

[rmuir]

we can remove the mvn install requirement so that it uses the "reactor" classpath in the future. it just means using a different property set by the maven build itself from that ant logic.