Fix tls_set_socket on WIN32

src/tls.c

@@ -2319,7 +2319,7 @@ void tls_cleanup(TLS_CONNECT *conn)
 
 int tls_set_socket(TLS_CONNECT *conn, tls_socket_t sock)
 {
-	int flags;
+	int flags = 0;
 #ifdef WIN32
     	if( ioctlsocket(sock, FIONBIO, &flags) != 0)   {
 		error_puts("socket in non-blocking mode");