Prep work for OPENDJ-1342: align APIs for DNs

Jean-Noël Rouvignac

03.25.2016 602b1987bab62b39cfce7d68d4f8e3b561fbc8a5

 opendj-server-legacy/src/main/java/org/opends/server/extensions/DiskSpaceMonitor.java

@@ -471,7 +471,7 @@
    }
    catch (DirectoryException de)
    {
      return DN.NULL_DN;
      return DN.rootDN();
    }
  }