Fix race conditions from Play Store (#1696)

Author: ButterscotchV

server/core/src/main/java/dev/slimevr/tracking/trackers/udp/TrackersUDPServer.kt

@@ -397,7 +397,9 @@ class TrackersUDPServer(private val port: Int, name: String, private val tracker
 		} catch (e: Exception) {
 			e.printStackTrace()
 		} finally {
-			Util.close(socket)
+			if (::socket.isInitialized) {
+				Util.close(socket)
+			}
 		}
 	}
 

server/core/src/main/java/dev/slimevr/websocketapi/WebsocketConnection.java

@@ -3,6 +3,7 @@
 import dev.slimevr.protocol.ConnectionContext;
 import dev.slimevr.protocol.GenericConnection;
 import org.java_websocket.WebSocket;
+import org.java_websocket.exceptions.WebsocketNotConnectedException;
 
 import java.nio.ByteBuffer;
 import java.util.UUID;
@@ -27,8 +28,13 @@ public ConnectionContext getContext() {
 
 	@Override
 	public void send(ByteBuffer bytes) {
-		if (this.conn.isOpen())
-			this.conn.send(bytes.slice());
+		if (this.conn.isOpen()) {
+			try {
+				this.conn.send(bytes.slice());
+			} catch (WebsocketNotConnectedException ignored) {
+				// Race condition if it closes between our check and sending
+			}
+		}
 	}
 
 	@Override