remove defoult value

Author: iddqdex

ydb/public/lib/ydb_cli/commands/ydb_benchmark.cpp

@@ -38,10 +38,8 @@ void TWorkloadCommandBenchmark::Config(TConfig& config) {
         .DefaultValue("")
         .StoreResult(&PlanFileName);
     config.Opts->AddLongOption("query-settings")
-        .DefaultValue("")
         .AppendTo(&QuerySettings).Hidden();
     config.Opts->AddLongOption("query-prefix", "Query prefix.\nEvery prefix is a line that will be added to the beginning of each query. For multiple prefixes lines use this option several times.")
-        .DefaultValue("")
         .AppendTo(&QuerySettings);
     config.Opts->MutuallyExclusive("query-prefix", "query-settings");
     auto fillTestCases = [](TStringBuf line, std::function<void(ui32)>&& op) {