THRIFT-4077: fix Appveyor warnings (VS2015) in PlatformSocket.h
Client: C++
This closes #1198
diff --git a/lib/cpp/src/thrift/transport/PlatformSocket.h b/lib/cpp/src/thrift/transport/PlatformSocket.h
index b8974ba..1890b60 100644
--- a/lib/cpp/src/thrift/transport/PlatformSocket.h
+++ b/lib/cpp/src/thrift/transport/PlatformSocket.h
@@ -23,6 +23,7 @@
# define _THRIFT_TRANSPORT_PLATFORM_SOCKET_H_
#ifdef _WIN32
+# include <winsock2.h>
# define THRIFT_GET_SOCKET_ERROR ::WSAGetLastError()
# define THRIFT_ERRNO (*_errno())
# define THRIFT_EINPROGRESS WSAEINPROGRESS
@@ -78,8 +79,8 @@
# define THRIFT_POLLOUT POLLOUT
# endif //WINVER
# define THRIFT_SHUT_RDWR SD_BOTH
-# if _WIN32_WINNT < 0x0600
-# define AI_ADDRCONFIG 0
+# if !defined(AI_ADDRCONFIG)
+# define AI_ADDRCONFIG 0x00000400
# endif
#else //not _WIN32
# include <errno.h>