compile fix

src/stream_output/stream_output.h

@@ -24,6 +24,9 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA. ***************************************************************************/
 
 #include <vlc_sout.h>
+#if defined( WIN32 )
+#   include <winsock2.h>
+#endif
 
 /****************************************************************************
  * sout_packetizer_input_t: p_sout <-> p_packetizer