It is a follow-up to https://github.com/jenkinsci/maven-plugin/pull/88

> We have a regression there when building a submodule of a Jenkins job, under Maven 3.3.9 we fail I believe because maven-plugin is calling Maven32Main while it is explicitely written on the command line Maven33Main.

> So I attached a remote debugger to it and the null pointer is caused at launcher.launch() where launcher is null probably because we are landing in the wrong class set by the builder