[MCOMPILER-457] Warn about warn-config conflicting values by pzygielo · Pull Request #153

[MCOMPILER-457] Warn about warn-config conflicting values by pzygielo · Pull Request #153 · apache/maven-compiler-plugin

I didn't want to change currently implemented logic.
MCOMPILER-457 happened to me as well. Caused some... confusion.

For future me, that does not remember that, it'd be fine to be warned about strange plugin set up.

Maybe when failOnWarning is true we also need to change showWarnings to true.

Maybe. I'd like to have the warning at least in such case as well, that parameter is updated out of my control.