fix bug: client core while low version server do not have profile_time

core/general-client/src/brpc_client.cpp

@@ -184,10 +184,12 @@ int ServingBrpcClient::predict(const PredictorInputs& inputs,
       oss << "op" << i << "=" << t << "ms,";
     }
   }
+  if (op_num > 0) {
     int i = op_num - 1;
     double server_cost = (res.profile_time(i * 2 + 1)
                  - res.profile_time(i * 2)) / 1000.0;
     oss << "server_cost=" << server_cost << "ms.";
+  }
   LOG(INFO) << oss.str();
 
   return 0;

core/general-client/src/general_model.cpp

@@ -449,10 +449,12 @@ int PredictorClient::numpy_predict(
       oss << "op" << i << "=" << t << "ms,";
     }
   }
+  if (op_num > 0) {
     int i = op_num - 1;
     double server_cost = (res.profile_time(i * 2 + 1)
                  - res.profile_time(i * 2)) / 1000.0;
     oss << "server_cost=" << server_cost << "ms.";
+  }
   LOG(INFO) << oss.str();
   return 0;
 }