setting the svn:ignore to match the plugins config folder

git-svn-id: https://svn.apache.org/repos/asf/maven/shared/trunk/maven-plugin-tools/maven-plugin-tools-java@525357 13f79535-47bb-0310-9956-ffa450edef68
tree: ec0ff860e733e24f22405c42fa37a002939fa8f9
  1. src/
  2. pom.xml