private String prettifyReason(String r) {
    final String str = "java.io.IOException:";
    if (r.startsWith(str)) {
      return r.substring(str.length());
    }
    return r;
  }
Processes the first startup response.

@see StartupResponseMessage#process
geode-core/src/main/java/org/apache/geode/distributed/internal/ClusterDistributionManager.java