Should SiteConfiguration getInstance be sychronized?

[David Medinets]

Findbugs is warning (Incorrect lazy initialization and update of
static field) about the following code:

  public static SiteConfiguration getInstance(AccumuloConfiguration parent) {
    if (instance == null) {
      instance = new SiteConfiguration(parent);
      ConfigSanityCheck.validate(instance);
    }
    return instance;
  }