keep en as site's default locale

git-svn-id: https://svn.apache.org/repos/asf/maven/plugins/trunk@1645434 13f79535-47bb-0310-9956-ffa450edef68
[MPIR-267] added check without failing, since it still needs to be fixed

git-svn-id: https://svn.apache.org/repos/asf/maven/plugins/trunk@1645436 13f79535-47bb-0310-9956-ffa450edef68