follow comments: more readable LOG

paddle/trainer/Tester.cpp

@@ -48,9 +48,9 @@ Tester::Tester(const std::shared_ptr<TrainerConfigHelper>& config,
       testDataProvider_(testDataProvider) {
   if (config_->getOptConfig().use_sparse_remote_updater()) {
     LOG(FATAL) << "It's prohibited to set sparse_remote_update "
-               << "in some layers if testing will be under going "
-               << "in the middle of training. You can do testing "
-               << "within separate process.";
+               << "when doing train and test jobs in the same "
+               << "process. You could run paddle --job=test in "
+               << "a separate process.";
   }
   testEvaluator_.reset(gradientMachine_->makeEvaluator());
   if (intconfig_->distributeTest) {