added translations

src/main/java/eu/mhsl/minenet/minigames/instance/game/stateless/types/playerRace/obstacles/Obstacle.java

@@ -48,7 +48,7 @@ public abstract class Obstacle {
 
     private static final List<Obstacle> remaining = new ArrayList<>();
 
-    public static Obstacle getRandomObstacle() {
+    public static synchronized Obstacle getRandomObstacle() {
         if(remaining.isEmpty()) {
             remaining.addAll(obstacles);
         }