message: fixes compile error in libcaf_openssl/middleman_actor.cpp on windows
diff: #include "caf/io/middleman_actor.hpp"
  +#ifdef CAF_WINDOWS
  +# include <winsock2.h>
  +# include <ws2tcpip.h> // socket_size_type, etc. (MSVC20xx)
  +#else
  +# include <sys/socket.h>
  +# include <sys/types.h>
  +#endif
  +
  #include <stdexcept>
  #include <tuple>
  #include <utility>
  #include "caf/openssl/session.hpp"
  -#ifdef CAF_WINDOWS
  -# include <winsock2.h>
  -# include <ws2tcpip.h> // socket_size_type, etc. (MSVC20xx)
  -#else
  -# include <sys/socket.h>
  -# include <sys/types.h>
  -#endif
  -
  namespace caf::openssl {
  namespace {
  