default void preUpdateReplicationPeerConfig(
    final ObserverContext<MasterCoprocessorEnvironment> ctx, String peerId,
    ReplicationPeerConfig peerConfig) throws IOException {
  }
Called before update peerConfig for the specified peer
@param peerId a short name that identifies the peer
hbase-server/src/main/java/org/apache/hadoop/hbase/coprocessor/MasterObserver.java