Fix build on Windows

NetworkServer.cpp

@@ -63,7 +63,7 @@ void NetworkServer::StartServer()
     if (WSAStartup(MAKEWORD(2, 2), &wsa) != NO_ERROR)
     {
         WSACleanup();
-        return false;
+        return;
     }
 #endif
 

NetworkServer.h

@@ -36,6 +36,10 @@ protected:
     std::thread *                   ConnectionThread;
 
 private:
+#ifdef WIN32
+    WSADATA     wsa;
+#endif
+
     SOCKET          server_sock;
 
     int             accept_select(int sockfd, struct sockaddr *addr, socklen_t *addrlen);