correct a mistake
correct a mistake

dmlc/rabit,dmlc/rabit,dmlc/xgboost,dmlc/xgboost,bssrdf/rabit,dmlc/xgboost,bssrdf/rabit,dmlc/xgboost,dmlc/xgboost,bssrdf/rabit,bssrdf/rabit,dmlc/rabit,dmlc/xgboost,bssrdf/rabit,dmlc/rabit