Make the example compilable for Windows

Author: kosmas-valianos

examples/client_server.c

@@ -1,7 +1,11 @@
 #include <stdio.h>
 #include <stdlib.h>
-#include <unistd.h>
-#include <arpa/inet.h>
+#ifdef _WIN32
+    #include <ws2tcpip.h>
+    #pragma comment(lib, "ws2_32.lib")
+#else
+    #include <arpa/inet.h>
+#endif
 
 #include "../src/proxy_protocol.h"