Avoid throwing many exceptions when attempting to create new hdfs encryption shim

  protected static final Method accessMethod;
  protected static final Method getPasswordMethod;

  static {
    Method m = null;
    try {
      m = FileSystem.class.getMethod("access", Path.class, FsAction.class);
    } catch (NoSuchMethodException err) {
      // This version of Hadoop does not support FileSystem.access().
    }
    accessMethod = m;

    try {
      m = Configuration.class.getMethod("getPassword", String.class);
    } catch (NoSuchMethodException err) {
      // This version of Hadoop does not support getPassword(), just retrieve password from conf.
      m = null;
    }
    getPasswordMethod = m;
  }