Fix: Added a timeout to NTR UDP socket

This fixes an issue where the thread could get softlocked if it stopped receiving UDP packets, and could not be forcibly stopped.
That became an issue after 710df6e, in which close() was changed to not close the socket.
I could have basically just reverted that change, but I think this is cleaner.

src/main/java/chokistream/NTRUDPThread.java

@@ -6,6 +6,7 @@
 import java.net.DatagramPacket;
 import java.net.DatagramSocket;
 import java.net.SocketException;
+import java.net.SocketTimeoutException;
 import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.LinkedBlockingQueue;
 import java.util.concurrent.atomic.AtomicBoolean;
@@ -62,6 +63,7 @@ public class NTRUDPThread extends Thread {
 	NTRUDPThread(DSScreen screen, ColorMode colorMode, int port) throws SocketException {
 		activeScreen = screen;
 		socket = new DatagramSocket(port); // 8001
+		socket.setSoTimeout(2000);
 		this.colorMode = colorMode;
 	}
 
@@ -166,6 +168,9 @@ public void run() {
 					secondaryExpectedFrame = 0;
                     secondaryExpectedPacket = 0;
 				}
+			} catch (SocketTimeoutException e) {
+				amIReceivingFrames = false;
+				logger.log("[NTR UDP] "+e.getClass()+": "+e.getMessage());
 			} catch (IOException e) {
 				amIReceivingFrames = false;
 				close();