Revive proper SIGINT handling

test/cpp/qps/worker.cc

@@ -71,6 +71,8 @@ using namespace gflags;
 
 static bool got_sigint = false;
 
+static void sigint_handler(int x) {got_sigint = true;}
+
 namespace grpc {
 namespace testing {
 
@@ -248,6 +250,8 @@ int main(int argc, char** argv) {
   grpc_init();
   ParseCommandLineFlags(&argc, &argv, true);
 
+  signal(SIGINT, sigint_handler);
+
   grpc::testing::RunServer();
 
   grpc_shutdown();