Exclude MLR by default

**Context**

- jGitVer 1.7.0
- maven 3.6.3

**Problem description**:

The README states a common pitfall when hosting the maven local repo (MLR) below the root folder of the reactor execution (i.e. where the pom.xml is). https://github.com/jgitver/jgitver-maven-plugin#build-fail-because-all-project-plugins--dependencies-resolve-to-the-same-version

The recommended workaround is to 'configure jgitver (using .mvn/jgitver.config.xml) to ignore your subdirectory MLR'.

IMHO this could be done automatically by jGitVer, since the location of MLR should be known to jGitVer during execution.

In my special use case I'm using Gitlab CI with docker runners, which by default put the MLR to the root directory (rootdir/.m2/repository) after checking out a repo and starting a maven build.

I can see no use case, where the MLR folder should *not* be excluded.