[FIX-PMD] maven-pmd-plugin: reactivate PMD - minimumPriority 1

Author: Vincent Potucek

.pmd/exclude.properties

@@ -29,4 +29,5 @@ org.apache.maven.impl.resolver.scopes.Maven4ScopeManagerConfiguration=TooManySta
 org.apache.maven.di.impl.Types=JumbledIncrementer
 org.apache.maven.slf4j.DefaultLogLevelRecorder=CollapsibleIfStatements,AvoidBranchingStatementAsLastInLoop
 org.apache.maven.artifact.versioning.VersionRange=CollapsibleIfStatements
-org.apache.maven.model.merge.ModelMerger=CollapsibleIfStatements
+org.apache.maven.model.merge.ModelMerger=CollapsibleIfStatements
+org.apache.maven.model.io.xpp3.MavenXpp3ReaderEx=UselessOverridingMethod