miniupnpc: Update to version 2.2.3

Library code and public headers are now properly separated, we can fix include paths
to remove the redundant subfolder.

thirdparty/miniupnpc/src/miniupnpc_socketdef.h

@@ -0,0 +1,44 @@
+/* $Id: miniupnpc_socketdef.h,v 1.1 2018/03/13 23:44:10 nanard Exp $ */
+/* Miniupnp project : http://miniupnp.free.fr/ or https://miniupnp.tuxfamily.org/
+ * Author : Thomas Bernard
+ * Copyright (c) 2018 Thomas Bernard
+ * This software is subject to the conditions detailed in the
+ * LICENCE file provided within this distribution */
+#ifndef MINIUPNPC_SOCKETDEF_H_INCLUDED
+#define MINIUPNPC_SOCKETDEF_H_INCLUDED
+
+#ifdef _WIN32
+
+#define ISINVALID(s) (INVALID_SOCKET==(s))
+
+#else
+
+#ifndef SOCKET
+#define SOCKET int
+#endif
+#ifndef SSIZE_T
+#define SSIZE_T ssize_t
+#endif
+#ifndef INVALID_SOCKET
+#define INVALID_SOCKET (-1)
+#endif
+#ifndef ISINVALID
+#define ISINVALID(s) ((s)<0)
+#endif
+
+#endif
+
+#ifdef _MSC_VER
+#define MSC_CAST_INT (int)
+#else
+#define MSC_CAST_INT
+#endif
+
+/* definition of PRINT_SOCKET_ERROR */
+#ifdef _WIN32
+#define PRINT_SOCKET_ERROR(x)    fprintf(stderr, "Socket error: %s, %d\n", x, WSAGetLastError());
+#else
+#define PRINT_SOCKET_ERROR(x) perror(x)
+#endif
+
+#endif /* MINIUPNPC_SOCKETDEF_H_INCLUDED */