message: fix core-testst
diff: @@ -52,7 +52,7 @@ TEST(coroutine, socket_resolve_with_cache)
  {
  coro_test([](void *arg)
  {
  - Coroutine::set_dns_cache_capacity(10);
  + set_dns_cache_capacity(10);
  std::string addr1 = Coroutine::gethostbyname("www.baidu.com", AF_INET);
  std::string addr2 = Coroutine::gethostbyname("www.baidu.com", AF_INET);
  @@ -67,7 +67,7 @@ TEST(coroutine, socket_resolve_without_cache)
  {
  coro_test([](void *arg)
  {
  - Coroutine::set_dns_cache_capacity(0);
  + set_dns_cache_capacity(0);
  std::string addr1 = Coroutine::gethostbyname("www.baidu.com", AF_INET);
  std::string addr2 = Coroutine::gethostbyname("www.baidu.com", AF_INET);
  @@ -82,7 +82,7 @@ TEST(coroutine, socket_resolve_cache_inet4_and_inet6)
  {
  coro_test([](void *arg)
  {
  - Coroutine::set_dns_cache_capacity(10);
  + set_dns_cache_capacity(10);
  std::string addr1 = Coroutine::gethostbyname("ipv6.sjtu.edu.cn", AF_INET);
  std::string addr2 = Coroutine::gethostbyname("ipv6.sjtu.edu.cn", AF_INET6);
  