added graceful stop for builtin webserver

src/main/java/eu/mhsl/craftattack/spawn/Main.java

@@ -84,6 +84,7 @@ public final class Main extends JavaPlugin {
             appliance.onDisable();
             appliance.destruct(this);
         });
+        this.httpApi.stop();
         HandlerList.unregisterAll(this);
         Bukkit.getScheduler().cancelTasks(this);
         Bukkit.getLogger().info("Disabled " + appliances.size() + " appliances!");

src/main/java/eu/mhsl/craftattack/spawn/api/HttpServer.java

@@ -23,6 +23,10 @@ public class HttpServer {
         Main.instance().getAppliances().forEach(appliance -> appliance.httpApi(new ApiBuilder(appliance)));
     }
 
+    public void stop() {
+        Spark.stop();
+    }
+
     public record Response(Status status, Object error, Object response) {
         public enum Status {
             FAILURE,