modify default value of use_ir_optim segmenter

deploy/cpp/demo/segmenter.cpp

@@ -39,7 +39,7 @@ DEFINE_int32(batch_size, 1, "Batch size of infering");
 DEFINE_int32(thread_num,
              omp_get_num_procs(),
              "Number of preprocessing threads");
-DEFINE_bool(use_ir_optim, true, "use ir optimization");
+DEFINE_bool(use_ir_optim, false, "use ir optimization");
 
 int main(int argc, char** argv) {
   // 解析命令行参数