RegionServerCoprocessorHost should be initialized before RpcServer starts

      // Try and register with the Master; tell it we are here.  Break if
      // server is stopped or the clusterup flag is down or hdfs went wacky.
      while (keepLooping()) {
        RegionServerStartupResponse w = reportForDuty();
        if (w == null) {
          LOG.warn("reportForDuty failed; sleeping and then retrying.");
          this.sleeper.sleep();
        } else {
          handleReportForDutyResponse(w);
          break;
        }
      }

      // Initialize the RegionServerCoprocessorHost now that our ephemeral
      // node was created by reportForDuty, in case any coprocessors want
      // to use ZooKeeper
      this.rsHost = new RegionServerCoprocessorHost(this, this.conf);