Receive: set timeout down to 10 ms (hack)

TODO: Timeout isn't in any case guaranteed to occur at the specified
time but can occur anytime after that. So occasionally it is not
triggered at all until the next frame arrival. This can cause that
2 frames' playout time passes at the moment. First one is displayed
while the second dropped.

src/main.c

@@ -536,7 +536,8 @@ static void *receiver_thread(void *arg)
                 }
 
                 timeout.tv_sec = 0;
-                timeout.tv_usec = 999999 / 59.94;
+                //timeout.tv_usec = 999999 / 59.94;
+                timeout.tv_usec = 10000;
                 ret = rtp_recv_poll_r(uv->network_devices, &timeout, uv->ts);
 
 		/*